Compression

A blown head gasket between 5 and 6 is a possibility.

All your numbers are low though. Was the engine warm and did you hold the throttle and choke open? Also, how many crank revolution per test. It can take at least three revolutions to build to full pressure.

You should test once and then a second time after adding a few squirts of oil into the cylinder. If compression increases more than about 10psi when adding oil it indicates warn out rings. If compression stays close to the same, then valves.

A leak down test would be the next step. But if you don't have a leak down tester you can do a poor man's test. If you can rig up a fitting to apply compressed air to the cylinder then you can listen for where the air is escaping. Oil cap = rings, tail pipe = exhaust valve, carb = intake valve.