horstman jackshaft

I am trying to disassemble a Horstman secondary and I am hoping someone here can point me in the right direction. Attached are photos of a Horstman secondary on a Terra Trail Topper mini bike. I have not been able to find an identical Horstman replacement and I want to keep the bike as original...

I am seeking a Horstman secondary for a 1970 Terra Trail Topper, please see attached photos. I am restoring this minibike and really need to find one of these. If anyone has a lead on a Horstman secondary, please let me know. Thanks!

Horstman Jackshaft 7 inch driven pulley, appears to be 5/8 belt, has bearings, hangers, 41 pitch sprocket, spacers.. As pulled from gokart. Clutch probably needs freed up but should work just fine... 50 plus Salsbury 7 inch driven pulley, appears to be 3/4 belt, 3/4 inch bore, might need to...