I'll start with disc clutch information.
Most disc clutches use similar diameter discs. These discs are generally .125 thick new. The differences are number of drive tabs, and disc diameter.
Horstman mdc.
The original 4 cycle disc clutch. 3.5 inch discs. 8 rounded tabs.
Horstman greased lightning, Noram cheetah, Tomar stellar, are 3.5 inch, 3 tab.
Vortec black are 3.5 inch, 4 tab
Bully, vortex red are 3.5 inch, 8 tab.
Horstman reaper 3 1/4 diameter, 3 tab.
Revolution 3 inch diameter, 8 tab
Tomar TD43-2 2 3/4 diameter, 3 tabs on floater plate. Outer disc, single side friction material.
That's a a start.