The compression does sound low for that engine and there is too big a difference between the high an low cylinders.
Unless the leak was so excessive that you lost four quarts of oil in 40 miles I would say that the rings are weak at best and you probably have worn guides and a few valves that aren't sealing as well as they could.
I'd do a leak down test to be sure of the rings and valves.
That will show you where the problems are and you can go from there.
