I can't help you out with your question, but maybe can offer up some advice on what to do with what you have.
To my knowledge, Blair didn't design his own circuits. He used circuits found in old publications. If you're able to spend the necessary time, you might get lucky and find what he was copying. Could take 2 hours, could take 2,000 hours.
Looking for another Beacon owner who could help you is a good strategy. Just know that many of his offerings were one-offs in one way or another. In other words, it is possible that no two Beacons were the same.
If, in the end, you're unable to build the exact Beacon, or the schematic therein, you have most of the parts there to make a preamp using another circuit. If I'm reading your pics right, you have four 6SN7s (a fav of Blaire, iirc) so you could find a mu-follower circuit online. You'll likely have to adjust the power supply circuity a bit. The red PCBs are for remote-controlled volume and relay-based input selector. If you don't have the accompanying remote you may want to scrap those PCBs. They'd need a separate power supply anyway.
The good news here is that you already have the most expensive parts; transformer, choke, chassis and tubes. You should be able to make a good, traditional tube linestage preamp for not much more money.
Good luck!
