I have an EVR 48 tooth clutch and I have to say that I don't think that tool would fit. The slots are semi-circular in my clutch and the teeth on the tool look trapezoid and too large to me.
That Vincent Goosey is a damn nice bloke to deal with. If you contact him he will give some good advice and is not adverse to making special one offs on request. He helped me out with some special Triumph tools and didn't charge me. (I had bought one of his tools for a special nut though and it didn't fit, he was happy to amend his specs for that tool and let me keep the prototypes.)
I fitted my EVR without a holding tool for the outer drum, it's not really needed and in any case it fouls access to the very bolts that you would want to hold the drum to tighten!
If you're replacing the steel plates then just use the old ones to make your own tool to hold the inner drum. I'll show you a picture of my tool if you ask nicely.
