My 16x64 Walcott has in the advertisement 32 pitches of thread with standard quick change gear box. It also claims "special", Extra fine, and Extra coarse, available with optional change gears. Well here is the real problem. I am just a hobbyist playing with old heavy iron. I have those gears, in the tool compartment under the tailstock. While the compartment is obviously shop made, its very handy. However... How do i tell what these gears convert it to? I am certain there was never a manual, the buyers already knew how it all worked. SO, do i just run these gears on some stock and measure or is there some way to calculate this?