Congrats on your new four screw! You did well on that one. If I didn’t already have a few in my stable, I would have been bidding myself.
That stuff on the safety valve almost looks like glue to me, like that stuff called “Seal All”. It might just crack apart if you try to remove the safely valve. That nickel should polish up nice and you’ll have a very nice piece. Can’t wait to see it all spiffy!