Getting down to the last little bits on my 1944 BSA M20 restoration.
I have two Lucas Voltage Regulators: a replica Indian made MCR2 (tall cover) and an original NOS Lucas 6v MCR1 L37 ER033053A (low cover) dated December 1949, but it is a side mount, not an end mount.
Do I use the Indian one or the 1949 NOS original?
If I use the original, I will need a pair of end ears to mount it to the mudguard. Where can I find a set or does someone have a trashed regulator I can take them off of.
Opinions welcome!

email (option): questmasters(at)hotmail(dot)com

When you say side mount! I guess it's the type that clamps round the frame tube?

The general experience of myself and other forum members is that the Indian MCR2's don't work for very long or are erratic to say the least. Personally I would take the end mounts from that one (if they're suitable and you have the means to reattach them) and throw it away. It wouldn't look right on your bike anyway. Ron

email (option): ronpier@talk21.com

Ron,
Yes, side mount / frame mount. I have only been working in the Commonwealth motorcycle world for a year now and am not completely versed in the correct terms.
Thank you!

email (option): questmasters(at)hotmail(dot)com

I'm not sure if these different bases have 'correct' names, but those of us interested have to find a way of describing them...I'd be inclined to refer to 'clamp-on' and 'bolt-on' bases...

As far as I'm aware, of the wartime manufacturers, the clamp-ons were only used on all Nortons and some Triumphs.

Are you intending to use the electro-mechanical internals ? The MCR1s had a suspect resistor and are hard to find in working order. If you're going to place a modern regulator in the box then I believe that you can use the early cover on the MCR2 base (if the copy is a good one. You'll have to satisfy yourself that the lettering etc. is acceptable.

Up until 1942 or so, the base should also be marked 'Lead-Acid'

Rik unless the Indian made base is smaller? I've found that it's not possible to mount an MCR1 lid on an MCR2 base as the overall footprint is slightly bigger. Ron

email (option): ronpier@talk21.com

Is it really, Ron ? I thought that I'd seen them mixed and matched with tall tops on old bases. Maybe there were Indian bits involved...

Rik you CAN fit a tall top on an old base, but it's a loose fit. As you can see here, an MCR1 top will sit comfortably inside an MCR2 top. Ron

email (option): ronpier@talk21.com