Mk1 mismatched front top mounts? (Pics)

[Boobonman]

Weird one, looking at the top mounts on the front of my car they appear to be slightly different. The OSF one has a thread that is almost half the size of the threads on all the other top mounts. The tapered end is still there so they haven't had the ends cut off, and they appear identical otherwise. WTF?

[VladD]

Pics from MX5Parts.

Mk1



Mk2



I'd suggest the left one in your picture may be a Mk2 replacement.

[Gilhooligan]

They both look like mk1 topmounts to me OP. Can't help with the different thread lengths though.

Edit: ask on the mx5nutz Facebook page. You'll get a pretty quick response.

[LordJammy]

One is from a car fitted with Bilsteins, they had longer studs on the top mounts for a strut brace.