We covered their bases while they were away, refueled their aircraft, provided critical intel, and weapons (Sidewinder air-to-air missile, Stinger man-portable surface-to-air missile).
There is a great old DoD paper on this I had saved on an old computer many years ago. I can't find it now, but I will keep poking around for it.
Let me re-phrase. By "overt" American assistance, I'm thinking of actual combat by pilots and their crews, naval vessels in the area, etc. By all means, if Maggie had asked for assistance I have no doubt we would've provided it.
But as a matter of British pride, it was to be a British fight. I don't think there's any doubt about that.