VX54NEW

Hi Gavin

Yes there is a difference,I fitted an aftermarket one,it only lasted 12 months.( I did have trouble removing old bearings though,so did not have the best start)
I then managed to buy a new old stock arm very cheap and picked up the fulcrum shaft of ebay for less than a tenner from (https://www.ebay.co.uk/usr/mg_rover_spares?_trksid=p2047675.l2559.)
The part number may be different but it does fit and is £55 cheaper than rimmers.
I have since in preparation bought another shaft for when the other fails and will use original bearings at £22 with new seals and bolts from a cheap after market one or the ones off the old arm if ok.
You can replace the arm with nearly all original parts for around £50 this way.
The first bearing is a sod to get out, but if you use a raw bolt of the right size and open it out in between the bearing races,
you can use it to drift out the first one, the other then is a piece of cake. Use threaded bar ,sockets and nuts etc to refit bearing races.

Regards Kevin