If you have oil in the cylinders there is no point in a compression test; it won't be accurate. Adding oil into a leaking cylinder is the test for leaking valve seals versus leaking piston rings.
NP, I'm not a perfect typist either.
You are correct that the head has to come off to access the timing chain, but I wouldn't pull the front of the engine off, just because I had the head off (I didn't actually), unless I knew I had a timing chain/gear problem; just my 2¢
Pulling the head is...
Several things: first, the 1FZ-FE doesn't have a timing belt. It has a timing chain:
Second, and take this for what it's worth, pulling the engine to change the headgasket is always a better option. Just wait until you have to crawl into the engine compartment to reinstall the head. Don't...