If you post some pictures, Cranky, we can discuss what is wrong. The diagrams I have posted are not clear, at least to me, in explaining the wheel drive clutch. It looks as if the clutch pedal, Item 28, operates a pull-rod, Item 30, which rotates a bell crank, Item 32. It looks as if an idler pulley, which I can't find on the diagram, mounts on that bell crank and tightens the V belt to engage the drive. Most likely something is jammed on your mower - and the most likely thing to be jammed is the bell crank, Item 30. If you pull and push on the clutch pedal whilst watching the bell crank, you will probably see what is and isn't working. If you post pictures of those bits with a comment or two on what you are seeing, we'll hopefully get there. When the clutch is working we can talk about what is wrong with the brake.
A ride-on mower is too big an object to operate without a reliable brake and clutch. You need to fix both.
