Thx Ron and all.

I'll keep scouring the Doka & related utility-military T3 network. Didn't base model Vanagons/Caravelles also came with rubber cab mats? Someone has to have a set, even if used. 

Or... I see some carpet sets are made of many flat pieces. I suppose I could find roll waterproof matting that can be joined with compatible tape+adhesive. Suggestions?

Removed the Dometic fridge at last; the space underneath was tightly packed with gravel, wood fragments and pine needles. No mummified critters like the one I found in the dash! Carpets don't have an easier life, and look it.