The SoS book shows 5 types of Sherman drive sprockets while the Sherman Minutia site has photos of the 4 main types. However, I've noticed a different pattern on some earlier Ford produced vehicles which differ compared to their usual D47366A casting. It is similar to the CDA produced D47366B but with the former's 'dimples'. You can see the sprocket I'm referring to here...

http://the.shadock.free.fr/sherman_minutia/manufacturer/m4a3ford/GMPG_8037a.jpg

and here...

http://the.shadock.free.fr/sherman_minutia/manufacturer/m4a3ford/3055617d.jpg

This is the more common Ford type sprocket...

http://the.shadock.free.fr/sherman_minutia/suspension/sherman_sprocket5.JPG

Anyone have some definitive info?

Thanks

Gary