Hello cyb... nice bike...!
I think most grey-beards will readily associate the name 'Amen' as frame makers from the 60's and 70's most famous for the 'Savior' frame which had a plunger-style rear suspension. I do recall them from being in California, as that was pretty much a hub of the chopper scene during that era. Your frame is not a 'Savior', but obviously a rigid with some stretch and rake. It's truly "old school"--- and I hate that term because it is so abused these days--- but check out the king/queen seat, the Invader front wheel, and the classic swept fishtail pipes!
If you're asking what the 'value' is, that's real hard to put a number on. No amount of dollars can probably equal the personal historical value of the bike, so I won't offer any numbers. To me, the value is in seeing a survivor from the early chopper days; what you have is a real chopper, not a cartoon-bike like you see these days. I'd suggest picking up a Service Manual for the bike, you'll need it to do routine maintenance and tune-ups. You can pick up reprints of the original manual for about 20 bucks here:
Antique Cycle Supply, Inc.ŠSERVICE MANUALS
You'll want the 1948-57 Panhead Service Manual.
Good luck with the bike, and you might want to check in at the Classic side of the AIM forums.