Usually a leak down test will give more and better info than a compression test. However, in this case I'd do compression test; both wet and dry. Perform a compression test, then squirt a good few shots of light oil onto the cylinder walls, wait a few minutes and test again. If wet compression reading is higher, then you have bad rings; if it's the same then valve guides are probably bad. Blue smoke on acceleration is usually rings, smoke on decel is usually valves. If valves, easy to pull the head and fix it.
