Congratulations on your amp find! I have a couple of these amps and they are great. Yours appears to be the later Crestline Falcon from 62 or so. Sometimes people will trash them for sounding thin and lacking volume. I think your wariness about finding a trustworthy tech and the $ involved in sorting out the issues has merit. I am somewhat surprised that the amp sounds as good as you say without any attention. If it is playable, you have several options. You can sell it as is.. or you could have it checked out by a local amp tech. It would cost you some money to do so but at least you would know what you have and prioritize your repairs. The 3-wire cord can be done when the tech is checking things out and should not be a huge expense. The reverb hum could be as simple as a tube (or cable) or as complex as replacing individual components. As others have advised you, the electrolytic capacitors (if original) are living on borrowed time. If they fail, they can take out your tubes and transformers. Gibson was infamous for using the paper "party" caps which according to some, was a bad idea from the get-go. The cost factor is why I started working on my own amps. There are a lot of helpful people (and a few not-so-helpful) who can advise you and help you learn. Ultimately, only you can decide whether this course is right for you. It is not easy...nor is it simple (as some have stated) but it is an excellent way to own, play through and maintain tube amps that otherwise would be out of our reach.