Are your numbers even between the two cylinders? If so, try a different compression guage. If it runs, then your compression couldn’t be that low.
Finding parts are not quite as bad as you might think. Fortunately, you came to the right place. There are actually a pretty good number of folks here nice enough to help out in some way.

No, there are no roller bearings in that. You don’t want to go leaner than 16:1 mix on that either. You’ll quickly nuke a rod and vent the block. They are good motors though. The integrated tank is a neat feature. Almost like a big brother to the Lightwin/Sportwin of the same era.
1954, they were completely redesigned with the full shift and everything below the powerhead base gasket, was interchangeable with the CD 5.5hp models, year for year. 1956, they were redesigned again with a whole new exhaust housing and such and still everything below the powerhead base gasket was interchangeable with the CD/Fisherman 5.5hp. Fleetwins were discontinued after 1958. They made a comeback in 1980 – 83 and were just like the 6 and 8hp of those years. Those motors were all roller bearing motors and ran on 50:1 mix.