Hi wane72. The cutter belt runs on the small bottom v-pulley (now) and the drive belt is on the larger top pulley assembly as seen in the 2nd and last photos.
Just got the machine going yesterday afternoon for the first time. It was on a small property and was going to be thrown out, so I got it to save it from being scrapped without knowing what issues it may have, apart from rust. Got the deck moving, pull-starter was jammed, rust and corrosion on flywheel and coil, rust and corrosion on plug end and plug top, junk and other horrid fluids in fuel tank, carbie bowl clogged with black gunk, jets cleaned out, and cutter belt twisted on not in the v-pulley. Compression tested at 100 psi. Did a few laps around the yard with cutter deck engaged. Not sure how the braking system works (yet), but the only issue I had was turning due to knackered and low pressure in the front tyres. Was a bit iffy to start with as it jerked forward when the pedal was pressed, but I got the hang of it after a while. Wasn't paying much attention to brakes and stopping. It just stopped/slowed down when I lifted the foot.