Yup, tapered, the old Bronze stuff.
Got extensive experience with them from this boat and previous boat, never had one get stuck this hard//
Not only have I tried to tap on the valve but have banged pretty hard while applying pressure on the handle with an extension just after heating
up the housing until funny
smells started filling nose above.
Sooo, the next step would probably be the PP blaster and if that ain't no good, then plug
the outside and try to remove the whole thing, then take it to a shop for dismantling and service
. (or replace with a modern version, like a ball-valve)
Thanks for the help, keep it coming and I will keep updating on the progress. (or lack of...