Hobbymat MD65 / Proxxon SD300 gears for automatic feed

I've got a very old Hobbymat MD65 desktop lathe but the changeable gears for the automatic feed are missing completely, so i decided to design my own.

Normally there is a set of single gears which can be combined onto a brass bushing, but the bushing is missing too.

Since i don't want to cut threads on this machine, i decided to create just a few gears with fixed ratios only for form feed. The usual ratios on the plate at the machine are 75-20 (pitch 0.08mm) for smoothing and 75-40 (0.16mm