I have four glass globes which have the very common 2 1/4" fitter diameter. Probably the most common size, actually...

I'm looking for some wall-mount "porch lights" (1930 or so vintage look) and everything seems to have a larger fitter, like 3 1/2", for example, like all the jelly-jar fixtures.

Are there reducing rings available anywhere to adapt a fixture to use a smaller diameter fitter glass globe? I have searched my usual lamp supply places to death and find nothing. My friend with a lathe estimates this would take him all day to fabricate.

Surely, there must be fitter-reducer rings available somewhere, especially down to 2 1/4" common size...