The 22-109 number i believe is the manufacturer designation for the 7 foot version of the 907 model ford flail mower, and built from 1962 to 1966. As such, some components such as the roller pulleys, most any major parts are no longer in stock. While flailmaster may stock the roller it would probably be easier to have one built.
Personally i run a five foot 907 model with the 22-107 designation and having had a driven pulley break, can attest to the fact ford no longer carries many parts for this mower. The solution to pulley replacement should they be needed, is purchase a C groove pully and weld in hub, though the problem being is the drive pulleys are oddball sizes with the drive pulley being 7.6 inches and the driven at 8.8 inches. The closest i could come was an 8 inch driven pulley so my mower actually turn's the drum a little faster than the factory gear ratio.
The really tough thing to find if needed is a weld in hub of the proper shaft size, as the shaft is 1 3/8 six spline. Parts can be found but are not common.
The biggest downfall of the 907 model is being single belt driven, in extremly tall heavy grass, you will get some belt slippage, which is why, i believe, this model was rapidly replaced by the 917 which run's dual belts.
All in all though, the 907 is a good mower, and with the correct knives will provide a decent cut. knives are fairly easy to sharpen, though replacement is a pain. All the knives in each row, are held in place via a stirrup and chain link that are mounted on a common rod that run's the length of the cutter drum, so to change a single knife the rod and all knife/link assembly's must be removed up to the point of the knife needing replaced. Not a big deal when putting new cutters in but not quite as handy as current generation flails where the knife assembly's are individually mounted to the cutter drum.
