I suspect that you already know all this stuff, but since you asked ...
I like my Pingel manual petcock but I also have SISF's overflow tubes as backup (yep, pull those danged carbs again for that one).
Pingel part numbers, maybe lost in the crash:
Fuel Valve 6211-CH
Adapter Plate A1702C (mates perfect to the Connie bolt holes and tank port - totally OEM appearing solution in chrome, includes all gaskets, bolts and sealer)
You must file the oval tank-port
very slightly to clear the 3/8" diameter pick-up and screen. I did this using out-strokes only and with my shop-vac blowing into the tank-fill to ensure no metal in the tank. This will NOT prevent re-fitting the OEM vacuum petcock if you want.