Oops, it looks like that one got dropped in the sand.
No, I don't know where to get that filter....although it sure does look a lot like the one on my 1958 vintage John Deere 530. I wonder if it is the same or related? You might ask over at Steinertractor.com.
Otherwise also ask Zoro.com. They have all sorts of odd mechanical parts and decent quality.
They also have a huge nvariety of oil filter adapters that replace your current oil filter mounting withn a more universal spin-on filter mount. Then you buy filters by whatever filter spec you want to use.
There was a time when ultra-filtered oil was popular. Shops used to use oil filter mount adapters to make up a multiple filter setup for what was called "Bypass" filtration. The bypass took a small amount of the oil as it flowed and sent it through an additional filter.
Adding that adapter might be the ultimate answer for your engine, because it makes finding filters easier in the future.
rScotty