Looking for a good source for anything related to Cadet 85 Super rider mowers, esp. manufacture dates by serial number.

I just collected the Ford 100 garden tractor yesterday and gave it a washed and a greased up. I have found some numbers on it which are very faint but I think they are 53059 1601 Here's are some photos of it in in current condition. Be great if someone can verify it built date or what ever...