P38A Rear view mirror compatibility between old and new parts

Hi all, I have a replacement auto dim rear view mirror as my current one does not work. I purchased it off flea bay and put it in my shed for a couple of years. I finally decided to replace it this week and only then found out that it is a different part from my current mirror and the replacement is the one that went on the later models and I think the L322.

Will the newer mirror fit onto the current mount attached to the windscreen. Current mount is square and the new mirror looks like it attaches to a pentagonal shaped mount.

Also if it does fit, the new mirror has a 5 wire connection (white/purple, green, Green/brown, blue/black and Black) where the old one only has 3 wires (White, Grey and black). Which colours do I splice together to get it to work?

Thanks

Pré and post 99 have two different mounting types but as for the wires I'm not sure to be honest. Are the plugs the same?

Don't worry about it. I posted in haste and researched at leisure. The answer is a firm NO to them being compatible.

Put it back up for sale maybe and good luck in your search