I spotted this clever display idea at a local antique mall: the dealer has put a selection of collectible pinbacks in a birdbath.
At home, of course, this might present a dusting problem (always the bane of collectors!), but if you used a sturdy cement birdbath, you could place a large round piece of glass or Plexiglass over the top. Like the kind used to make those round boudoir tables.
The clear covers would keep dust, pet hair and other contaminants out (and, if UV protective, damaging sunlight too) while still allowing the collection of vintage lithos, celluloid, and metal pinbacks to be on display. This would work well for housing and displaying vintage and antique buttons and other small bits and bobs too.
Imagine it as an end table, next to your sofa or chair, with a little vintage lamp on top, lighting the contents, inviting guests to look inside. A very charming conversation piece!