Wow, how did I miss this thread so long ago?
I'm already well ahead of you, though I doubt it would be a worthwhile business opportunity. Just Dashes will, in fact, take a W123 dash in and cover it. Grain patterns would not match the original, but hey, does that really matter, since the glove box door could be refinished at the same time? As long as the two match, the difference between original and recovered would be trivial.
The problem, as I see it, is that no one want's to pay close to $1,000 after shipping just to have a crack-free dash, when most W123 owners are A) unwilling to spend that kind of money on the motor, much less a dashboard, and B) are content with buying crack-free originals.
Me? I despise dash cracks, so I want them gone! Will I pay Just Dashes more than my car is worth to have one restored to non-original finish? No way. Besides, it violates my DIY spirit! I also don't see the logic in buying an original, but crack-free dash, because after 25 or 30 years, they are brittle, whether they have cracks or not! So...
I have in the past built one-of vacuum tables and used heatable vinyl and plastic to re-cover small items, like door panel inserts and armrests. Never have I attempted anything so large as a W123 dash, but, that won't stop me from trying. The project isn't exactly on the front burner, but it is in the works. Should my efforts prove successful, I figured I would offer the service to a small number of forum members for right around cost, as a sort of hobby/service to the community. I've estimated that the material costs for an actual finished product would be similar to the shoddy dash caps that are available.
The problem I am having is longevity... I can't say how long a fresh vacuum-formed vinyl skin would last. No one that manufactures the stuff deems it worthy of receiving any sort of rated service life.
