Odd aluminum serial number plate on old Sunbeam race motor

[Steven Silverstein <milano164@mediaone.net>]

I pulled the engine in the old Sunbeam race car I am restoring.
I thought that the block had a crack (in addition to sitting for 32 years)
because there was an 2x5 aluminum patch on the side of the engine below the
generator.

Actually, this is a serial number plate but not a Rootes ID number.  Did the
SCCA require some sort of ID plate on the engine block?

The other possibility is Wacholz, who did the precision balancing also added
an ID serial number plate.   This would be similar to the head on this car
which has a "Mondello's" stamp and serial number (and I thought they only
worked on Oldmobiles).

Thanks,

Steve Silverstein