Hello Greg,
The red colour, the Agricultural look and the way the cutter system is set out sort of indicates to me that it could be off a sixties Wheelhorse or Simplicity tractor. The decks on these units came seperately as an accessory. Most of these decks had a heavy guage cover plate over the pullies, does it look like it used have one but is missing? The reason the pullies were protected was because you drive the tractor over the deck to fit and remove it. Hope this helps.
Cheers Keith.
