Should I have my beaded purse framed?

My opinion on this is a definite no.  A beaded purse is, after all, a textile item, as it is made with thread.  Usually, linen thread was used.  Linen is a very tough natural fiber (from the flax plant) and has great longevity.  However, when a purse is sealed up in a frame, the air inside the frame is trapped, and becomes stale.  Stale air actually speeds up the deterioration process.  It is best to let the air circulate around a beaded purse, or any other textile item.  You do not know if the item ever received a spill of some kind, imbedded in the fibers, which may not be apparent, but this is where a chemical reaction will occur first...

A related example:  I know a lady who collected vintage Celluloid hair combs, the ones with the rhinestones.  She had a very large shadow box frame custom made to display them.  It hung on her wall for years, then one day, she noticed they they were all crazed and crackled.  One had had "celluloid disease" and it had been passed to all of the combs inside the frame.  Her prized collection was lost.

If you feel the heirloom purse in your family needs to be protected for future generations, then place it in a frame with a hinged top, so you can open the frame and provide fresh air on a regular basis.  Or put it in a vitrine cabinet--the kind that sits on a table, or is actually already a table.  Then your purse will not have dust fall on it or little hands touching it, and you can open it regularly.  

Most collectors of beaded bags just hang them on the wall, with nails, pretty tacks or hooks.  I think this practice is fine.  Your purses will occasionally have to be carefully dusted....but you will be enjoying their magnificent beauty every day.  In this way, you are displaying them as they really are:  works of fine art.  

The only type of purse that you need to really be careful about is the steel beaded bags.  The steel beads are far heavier than glass, and they put a greater strain on the linen fibers.  Steel beaded bags can be hung, but they should also be 'rested', taken down every few months and laid in a drawer or box for a few months, then returned to the wall.

I have beaded purses hanging all over my house, except in the kitchen.  I even have had them hanging in the bathroom, however, we did not have a shower, so the room never got steamy.  We recently totally remodeled our bathroom and put in a shower and now there are no beaded purses in there anymore.   A powder room would be a lovely place to hang beaded purses.

Changes of temperature are the big factor when you're considering preservation.  In our modern homes, temperatures are relatively constant, season to season.  So as long as your purses are not in a basement (too damp and cold) or in an attic (too hot and dry) they will last throughout your lifetime.

Thinking in a pragmatic way....all textile items have a life.  We don't know how long that life may be, but why place your pretty beaded treasures in acid-free tissue and store them away in boxes or drawers?  You should see and appreciate these works of art every day.  So hang them and enjoy them!  After all they are YOURS.

How were they made?

Given that website visitors don't like to do lots of reading, I'll make this answer short.

Beaded purses are made in basically two ways, either knitted/crocheted, or created on a loom.  (all steel beaded bags are done on looms)

With knitted beaded bags, often done by master knitters, in which one thread is used, the maker would carefully follow a pattern, threading up to a third of the purse's beads at once, then knit between them...(Amazing!)  If you made a mistake in the threading process, your mistake would not be apparent until the bag was practically done--oh, oh! The real tricky part was keeping the tension uniform, as one would knit day to day, picking up and putting down the project until the purse was done.  If the tension was not constant, it would cause the purse to turn, or twist, rather than laying straight for optimal beauty.  Imagine working on these purses, finally finishing one side, and then you'd have another side to do!  Some purses have hundreds of thousands of beads.  They are miracles of patience, concentration, and the stamina required to make a profession of purse knitting is astounding....let alone the eyesight!  And they didn't have the brilliant light we have today!

With loom purses, once the loom is set up, each bead is threaded and  one row is made at a time.  

The difference between the two techniques is only important when a purse requires repair, for instance, a hole.  If a knitted purse has a hole, then the repair is done by carefully drawing the hole closed--if not too many beads are missing, then the hole can be closed to prevent further bead loss, however, a little pooched up spot is bound to be there.

With loomed purses, a 'hole' is much more serious.  When the rows separate, they can not be readily repaired since the threads have passed through the beads from both  directions.  If rows are separating that is an indication of dry rot (weakening of the fiber) in the thread, and trying to sew and attach to what might look like stable nearby rows, might actually cause more damage, as those rows pull away.

I recommend seeking out a professional beaded purse restorer for repairs.  

How can I (should I) brighten my dull-looking, or tarnished purse frame?

Whether to do so or not is your choice.  Some collectors like theirs looking bright and new, others like the aged patina.  Gold-colored frames are usually made of jewelers brass, which does not tarnish and retains its original patina to this day.  Better leave those alone.  They look the way they should.  This question usually refers to silver colored metals, which can dull with age.

If you do desire to brighten the frame, do NOT use paste polishes--not only will the paste likely get into the crevices and later dry and turn green and be hard to remove, but worse than that, the paste may easily get into the beadwork and the chemicals within it cause damage to the threads, which cannot be undone.  Best to use four zero steel wool, and--lightly and carefully--rub the frame.  Then blow the tiny bits of steel wool away, so they do not get lodged into the purse.  (Check with a magnifying glass for remnants of steel wool).  After this process, wipe the frame with a very soft cloth, because there is oil in steel wool, to keep it from rusting.  This oil should not be left on the purse frame.