Thank you AV8TOR,

The point about a rigid coil mount has been on my mind for a few days. At present my inclination is to use a piece of 1/4" 7075 T-6 plate with a "strongback" on the outboard edge. It was also my intention to re-locate the original mounting a few degrees outboard to increase cylinder cooling. I've had pretty good luck ( so far ) pressing apart crankshafts and changing the keyway index.
However, I may not pursue that mod as many conversions seem to cool fine with the coil in its original mounting.

I've considered making a conversion thread but not sure it would be of much value to the readers as I have no expertise in these matters.

Azurak