Yeah, the thing with Dumble amps is no two are identical. He built each and every one of them for the particular artist. It's not "a" Dumble, in the sense of one Fender Twin Reverb being a member of a large population of such amps produced. It's "your" Dumble if he made it for you. If you buy someone else's Dumble, it's still that artist's Dumble.
I've seen the insides of an ODS and a couple of Fenders that Dumble modified. He had some general approaches that evolved over time, but each and every amp he built was a work of art, intended for a particular person to play and tailored to suit that player. He also rebuilt amps when they got sold to a different artist, in fact he recommended that as a way to get the amp quicker, rather than a scratch-build.
The Dumble estate and name are being curated by the Dumble preservation association and they're trying to make new ones with the name. I have some doubts, since the man himself isn't around anymore. I hope they can protect his name and reputation though.
There are some "clones" of Dumble amps who's schematics have leaked out. ODS #182 is probably the most "cloned".