The red one looks complete to me (except for the missing mower deck, of course). If you get it working, you'll have one to copy to get the first one complete and working.
I'm guessing that the previous tenant of your first buy threw away the whole cutter clutch system when he ditched the mower deck and made it into a tractor. Tenant's improvements, of course. I don't suppose he kept some of those parts did he?
