what a useless answer seriously..
pretty much what you said mate,its ya gaskets and oil pump that are the killer for these engines $$$$
drop ya head of and block and a machine shop get hear recoed and bores cleaned up they then can tell you wether need oversize rings and what not.
also water pump, timing belt, thermostat and housing best to do everything whilst its out.
good luck with it mate, love the 20's