There are quite a few permutations of the shift surrounds (owing to the numerous shift-gate patterns used over the years by MB.) So, you have to be very careful about buying replacement parts for your surround since the size of the rectangular shift-gate openings vary (DON'T ask me how I know
Anyway, while I don't know exactly which surround your 190 uses, I do know that many of the earlier surrounds were sold as a single unit (with the rubber frame/insert cemented in place.) The rubber piece wasn't/isn't available separately. Subsequent years' models had separate plastic frames that could be purchased on their own (or replaced with aftermarket chrome alternatives.)
From your description, it sounds like:
--yours was one of the "integrated" earlier types;
--that only the visible part of the cemented rubber "frame" was removed;
--and that the "teeth" you're seeing are what was left of the original rubber by whoever performed the "surgery".
If my assumptions above are correct, and if my experience is indicative, you'll probably have a tough time tracking down just the rubber piece you need. You'll more likely find a complete used wooden surround on eBay or in a junkyard (as noted, make sure it's compatible before you buy it). You can then decide which wood is in better shape (most of the surrounds eventually develop cracks), and mix and match to get the best results, swapping/recementing rubber as necessary.
Hope this helps.