yup,Ike I said, "I'd love to see another similar Interior to what I've acquired"^^

 

Here's all the standard issue interior materials options for the 1982 Porsche line, there's nothing like your interior on it. Which is consistent with the '99' interior code.

 

The back seats have the design of the early sport seats but these are rare.

 

Dove into my factory lit, I have info from '83 and '85, I thought this was the latter but will recheck:

 

definitely not any of those. I find it interesting that no-one has anything on this interior. I have yet to locate photos of anything similar and I've been looking constantly.

 

I would've thought something would have come to light here, by now. Hm, @Drooman ?
It's a great acquisition, even more so if it was some sort of design study or if there's a story to come to light about an otherwise custom/owner specified interior.
After looking, image above is from an 85/86 brochure. Seemed to me to resemble brown pinstripe flannel, but you have the real world visibility on it (in addition to the model year offset).
Maybe that '99' code that Rob identified is simply a placeholder for 'custom'? Dovetailing with the 'factory use'? Maybe FOIAing the records of past registrations/inspections would be interesting. Or try starting a dialog with the 'mother ship' by applying for a COA or regional PCA POC. Anything different/distinctive on the build label under the hatch carpet? Must've already checked for VIN in the 928 registry?

 

My 86 brochure info.