[Mgs] Crank shims for MGB

[mike at duvallvideo.com (Duvall Video Productions)]

I bought the expensive Payen gasket set for my B rebuild.  Unfortunately I
discovered the thickness is substantially greater than the original and that
moves the front plate away from the block which shifts the position of the
cam.   Checking my sprocket alignment shows I need .020 or so of shim to bring
the crank sprocket into alignment.

Moss and British Victoria both show shims but doesn't say how thick they are.
Anybody know if Napa sells something that would work or dealt with this
before?