Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

I don't think it is a screw....just a pin.

I had a #45 whose 'screw' was probably a stickpin
cut to size and set into a hole drilled into the
crank throw.  Still had the head on the pin.

This may be a time try something unusual.  You might
look through the listings at 'Classic Tin Toy co'.
They stock all sorts of old toys/parts, including those
for steam engines and reproductions of original parts
such as the following...
'Weeden Engine Eccentric Crank handle 1/2" reproduction'.
I bought 2 and used one.

Get 'em while you can.  I don't know how long this
company will be around.

Good Luck,
Wayne