Thanks Andy.
That's some good info on the R2/4J and the R5/6K. I'll look on the frame for a machined area for the torque arm tonight.

Appreciate the advice on the seized engine as well, trying to free it up could have been a coslty mistake!

I got her way below what I expected to pay, but like most bike projects, I'll be tossing money at it where I can.

Need to get it up and running is my first priority.