The next diagnostic step will be to do a leak down test. You'll need access to a compressor and an adaptor (cheap simple tool) that screws into the spark plug holes. Rotate the motor for each cylinder so the piston is at the bottom of its stroke--valves closed. Connect the air line to the adaptor and listen for where the air comes out---carbs (intake valve)---exhaust pipe (exhaust valve)---oil cap opening in valve cover or oil separator at pcv connection (pistons/rings).
You just never know what you'll find. Personal example--the B20 in my '69 144--ran fine on the street but had run on track days for two years with oil pushing issues (leaks from front and rear crankshaft seals) but still had performance enough to run 100+ mph and easily to redline+ rpm. Performance at a new track in NJ did not come to expectations so at that point I opened it up. I expected to find a broken ring (oil pushing)--found top rings in 3 + 4 broken. My leakdown test indicated other problems as well and the results of teardown showed one intake valve starting to burn (very rare--probably due to high rpm and a bit of carbon stuck on the valve) in cyl.1 and one exhaust seat receding in #2. A valve job with hardened seats for the exhausts and pistons/rings have restored my motor.
Wonder of wonders--the carb fiddling I used to have to do is now a thing of the past.
As for the cam being worn--this could easily result in very high compression numbers as the valves have very little overlap with the standard cams. I've seen 240 across the board in a B18 that had a totally wiped out cam.
If your performance is satisfactory and oil consumption/leakage reasonable I'd just drive it till it really needs attention--start a rebuild fund now. -- Dave