Touche' my friend. I don't have a set of tube wrenches . . . but never met a tool I didn't like. Might pick up a set next trip to Wichita.
In the mean time, a more drastic move (cut the line) got the cover off, cleaned, gasket bonded and replaced in good form. I really DO like those valve covers. Three, centrally located hold-down screws that tighten up against internal spacers. The last time I fought a cover leak was on a Chevy straight 6. Tightening those cover screws correctly was like learning to play violin . . . and it was before silicone gaskets.
I'll put a short piece of 3/8 hose on the tube to restore brake vacuum.
My next step is to put all that compressor support bracketry back on, install new compressor, suck down the system and recharge it. Summer is just getting warmed up here in KS . . . I really don't enjoy the Model 270 a/c (2 windows down, 70 MPH) . . . it blows my cowboy hat off.
This is a really cool forum . . . I'll be replacing a dash cover next after refurbishing the vacuum operated, HVAC doors . . . but not until the weather cools off. I'll be back to bug you guys again then.
See
http://aeroelectric.com
That's what I do in my parallel universe . . . if you've got any DC power system issues, I herded electrons on airplanes for 45 years before retiring to cow, oil, wheat and cotton country. Here's #5 grandson getting a driving lesson in his great-grandpa's 87' GMC.
http://tinyurl.com/jhmwbxe
Maybe he can drive it on his first date . . .
Thanks!