Harmon Kardon citaion 1 kit telefuken

I think you have something that is very very rare and collectable if it is in good or better condition. If the kit included the original unused tubes which I assume is why you put Telefunken in the title, then it's even more collectable. I would think you could sell it for a very good price that would give you the money you can use to buy what you want.
The guy with the most knowledge is probably Jim McShane who you can find on Audio Asylum, or under his web site name of McShane Design.

A collector item it is. A great sounding unit it is not. The parts are now so out dated that its 'sound' would not match most current offerings. VAS audio, has taken the design and put in new state of the art parts and produced a Citation I pre amp. I have one. Sound great.

You would certainly have to reform all the electrolytic filter caps and hopefully they are still good. Given the age I would doubt it, as they dry out with age. All I remember about it was the circuit was very novel for it's day. The output transformers were also quite good.