You are probably going to need to cut your own. I know that Morgan at Cameraleather has some thin vinyl pebble material that would work well in this situation. The issue will be cutting, and possibly needing to use a heat gun to get it to set down if there are compound or tight curves. Use thin paper to make patterns, especially if you need to wrap corners on facets, etc. And accept seams, maybe not where they were originally.
Zeiss often used a weird fabric/plastic material, also very thin. Well, I think it is plastic, maybe someone knows how they got the pebble texture on the top of the fabric backing.