Many of us had dynotuners do custom air:fuel maps for our Warriors. I had several done. I also got very good at tweaking the tune to match changes in mods. Lots of guys here did the same. So a customer map by itself would not be an indicator of internal motor mods.
The service manual details how to manage the decompression solenoid hardware to allow a compression test. Also, as was stated already, remove both spark plugs from a jug, shine a light in one and peer deeply into the other.
This motor, stock, runs very powerfully on regular octane fuel. For some mystifying reason many folks use high octane fuel anyway. If you do, then try running the tank low so fuel light comes on, then add one gallon of regular octane fuel and if the motor does not ping then its standard compression pistons. If it does ping its okay you have room to add high octane fuel to correct.