Check in the Cooking forum. A ot of people have Nesco roasters that they use as crock pots, and maybe those have inserts. But Ive never seen it in regular crockpots.

Oh, you mean the Nesco 3-piece buffet, such as on amazon?

Not quite what I meant, but interesting. May I assume that my type of crockpot is outdated, so they'd never make such inserts for such pots anyway?

What a pity, cuz it'z very very convenient, if only the alum. pan were easily washable the way teflon would be.

I wonder if there's any regular teflon pans which are the exact dimensions of above pan, AND whether a metal worker could do the same for me with the teflon pan as I did on the above.

But go find a metal worker. And go find one who would do it affordably!

UPDATE:
OK, this discussion is continued on the Cooking Forum
(see thread via below link)

Here is a link that might be useful: Continuation of this discussion on Cooking Forum