I'd like to add my comments to this discussion having recently changed the gearbox mount on my 1850 ( same as the Sprint ).
It was coming up to MOT time recently and in doing the usual checks I found the gearbox mount was soaked in oil and breaking up. Not good when you have an MOT booked for the following week. I noted Mr Rimmers do it so I ordered one on the grounds it may be a hard rubber and thus noisy but at least it wouldn't fail its MOT. It arrived 2 days later and fitted no problem.
At the same time I ordered the Lotus Elite part which is identical but Lotus parts always take many more days to arrive.
Now I was pleasantly surprised by the Rimmer's part. Yes the rubber was rock hard but the drive to the MOT place was no noisier than normal, and 2 weeks on and a few miles further I would not have faulted it.
Now the Lotus part has arrived ( B075F6001Z ) and just with an empirical fingernail test on the castellated rubber bit , yes it is much softer.
Am I going to change it ? No . I'd like to see how the Rimmer's part lasts.
I think there has been a change.
The Rimmers part came in a bag labelled " RTKC1044 TR7 RR Eng mount TKC1044Z & Made in India " but with a 2nd label "TKC1044 Gearbox mount , rear "
The Lotus part was embossed in the rubber with "BJS" in an oval logo.
I Googled it and found this company based in Wales.
http://www.bjsparts.com/
It looks like they are a major manufacturer to the automotive sector and are U.K. based !
Remind me in 5 years time to update this with any news.
Tony.