A7 / A10 Flywheel compatibility?

[BritTwit]

I've just acquired a NOS A7 crank (67-0385) 72.6MM stroke.  I have a spare flywheel from an A10.  Is it the same as the A7?  I'm sure it will need to be re-balanced.
Comments?

[muskrat]

G'day BT.
That's a good question I can't remember being asked before.
I would imagine it could but as you suspect the balance would be way off. Will be interesting to hear other members thoughts.
Cheers

[Peter Gee]

It will indeed need fairly radical rebalancing,  which will prob involve adding weight - not the easiest of tasks compared to removing.

If they are dimensionally the same is  something left to the wizard experts on this site, because googling the part number returns zero results. That is very rare. I suspect the very early A7 cranks may have differed but IMU (understanding) the "small journal" size was common to A7 and A10 right through the 1950's.