Rear seatbelt buckle - rubber "doohicky" replacement

[deezulmark]

W123 - 85 300TD
Is it possible to install replacement rubber doohickies on the rear seat belt buckles? My new to me wagon came without the third seat option and 2nd row seats without headrests (or holes to mount them in). My kids are tall enough now to need headrests for whiplash protection and I was able to get a salvaged 3rd row seat and related parts AND 2nd row seatbacks WITH headrests.

However, the "new" seatbacks have two out of three of the rubber doohickies gone while all three in my original seatbacks are still intact. If it's possible to pull that plastic ring off and remove or attach the rubbers, I haven't figured it out yet.

An item like that is somewhat breakable so you'd think MB would have designed them to come apart somehow for replacement.

Anybody out there suceeded in this area? I saw another thread that replaced rotted/broken ones with thin shock cord and jammed them into the holes with rubber stoppers. But since I have intact rubbers still, I'd like to move them to the other seatbacks if possible.

[disqo]

I know this is an old thread, but I am looking for the same info. Anyone?

[sknittymama]

Did you ever figure this out? I too saw that thread about using shock cord and rubber stoppers, but can't seem to find it again. Any help appreciated.