The readings all look good I believe, so it would seem that your power supply and B+ rail are functioning properly. If the bright channel is now working properly, I would focus your efforts on the wiring of the other channel. There must be a bad joint or wiring error that is affecting only that channel. The normal channel runs from the input jack, through one half of v1 and then mixes with the bright channel at the volume pots. Recheck everything between those two points. I would also give some thought about shortening some of the leads to the preamp tube sockets. There is alot of extra wire length from different stages laying parallel to each other around those sockets. You want the most direct path to the socket without putting strain on the wiring.