Possible blown head gasket or worse

Update:

I drained the oil today and to my surprise I did not find any metal in the oil. Also I didn't find any water in the oil. It seems to be burning oil though... It only had about 3.5 quarts of oil in it.

Do I feel it is still a blown head gasket? I feel it has to be, right?

The reason I didn't see any water in the oil could be do to the very leaky water pump? Can't circulate water if there is none.

I'd like to run a compression test, not sure how to go about it seeing that it takes a bit for it to actually crank, only does quarterish cranks In the beginning. Plus seeing I just dumped oil out of it.

The loss of oil could indicate burning oil through the cylinders... Probably not an oil leak.

I have no idea how many miles are on this engine. It's numbers matching and the odometer reads 700,000 something. So it's maybe been rebuilt 2-3 times?

Off with the head now? Or try the best I can to run a compression test?