Congrats!
I do not think I have seen a cat biased 2xEL34 amp before. Will be anxious to see how your chassis progresses.
Good Luck

MacG -
Your pictures made me laugh....!
If I had seen these first, I would not have suggested you check your wiring; I would have just said to swap your OT wires. That is a real square build job! It looks like one of Nik's guys put it together. Very clean, tight, tidy, and neat.
Just curious.... are your heaters green? It is hard to see through all of the FX and  speaker jacks, impedance selector and bias jacks, etc.
I am impressed, there is a lot going on in those chassis'. As the old saying goes, It looks like a good neighborhood to live in.
Good Luck

Usually, oscillation gets worse when the Presence is increased. Make sure you have the NFB/Presence circuit wired correctly. If it looks like you have done it all proper, I would swap the OT wires on your power tubes. Just unsolder the wires on Pin #3 of your power tubes and swap them, one for the other. Brown goes to Blue, and Blue goes to Brown..... or whatever color you used for the Pin #3 hook up.
Good Luck

Those are pretty popular amps, and this forum does get a fair amount of views.....But aren't you suggesting a rather difficult project. I might be way out of bounds, but aren't these two chassis' 180 degrees opposed? Seems like your old combo is the typical top mount with the tubes hanging upside down. But I think most of the 18 watt TMB chassis' are mounted on the bottom, usually in a head, with the tubes oriented in the other direction.  Maybe that is why you have not gotten a respone.....??
Like I said, I do not own either of these amps, so I could be completely wrong....
Good Luck

Wow!
I must say, that is about the classiest logo I have ever seen. Maybe you should talk to Nik.....??
Are you able to produce these logos in large numbers? Are they running from 6 volts or from the wall voltage?  I am just thinking, Nik ships all over the world, it would probably be best if it ran on 6.3 volts.
But maybe I am putting the cart in front of the horse 
Best

Absolutely -
Nothing specific, but any and all of them. Ampeg, Magnatone, Rickenbacker, etc.
Offered as a head and/or a 1x12.
There are WAY more people recording today than there were in the 1960's-1970's (or the 1990's for that matter). The more 20 watt and under the better; as far as I am concerned.
Good Post Emiel

Pics and video.....
I would love to see the Ceriatone facility, and talk to the OCD character who does all the heater wiring. My builds/lead dress are pretty good, but I want to meet the guy/gal that wires those heaters.....
You Lucky Bastard.........!!!

I cannot not confirm anything, you would have to email Nik these photos. The hand work in the chassis definitely looks like Ceraitone assembly. You do not see a lot of work that tidy. Some of the components seem odd To Me for a Ceriatone. The indicator light and impedance selector knob also look like non-Ceriatone parts. Maybe this was a very early build from Nik, and somebody slapped their logo on it with a few parts changes also.....?
It looks well made. How do you like it?
Best

Better wire.....?
What does that mean exactly?
From reading your post, I would say you will hear a pretty big improvement when you install the Sozo caps.
Good Luck

Are you guys sure you are on the same page...?
To my knowledge, the original BF Princeton did not have screen or grid resistors. It looks like Nik has 1k5 resistors on the grids of his build. He "designed" this layout so I would assume they were a good idea.
Pin 4 is the Screen grid.
Pin 5 is the Control grid.
Good Luck

Not to take away from your excellent playing, and it is excellent......but your recordings are so good!!!  What kind of recording stuff/mics are you using?
Thanks

It makes it  easier for guys if you would post schematics/pics of your concerns....
Good Luck

T.C. -
That is interesting info. There seems to be an infinite number of tone possibilities with a 5E3. Well, not infinite, but a lot. I do not know of any other amp's tone stack that evokes so much mystery/ignorance/frustration/and enjoyment. Greg V does a decent video with a 5E3. All his videos are worth watching. He is a very capable and tasteful player.
Thanks Again TC

Regars the 100r, you can try the tone stack both ways and see what you think.
The diodes and cap are a protection circuit for the rec tube mainly. The SB Switch can kill the rec tube with in rush/spikes.
There really is no reason to use the SB switch during normal amp use. It is a useful tool when working on the amp; to be able to disable the HV. But as far as using the amp to play guitar, I just leave the SB switch in the off position all the time. I turn the amp ON and OFF with the power switch.
Good Luck

I am not sure I really see a question here. Sounds like you have everything under control, just need to put in a fair amount of time with the different speakers/cabs. Does your attenuator limit you to a 4 ohm cab, or does the 4 ohms refer to the impedance of the amp?
I can tell you that the Wizard/Governor combination is hard to beat. It works well with a lot of amps and a lot of music. I know you bought your Scums used, but the owner, Jim, is a pretty pro-active guy. Speakers are what makes his world go around, he will be happy to discuss your Scums via email. I would encourage you to give him a shout.
So I do not really have any advice for you. Sounds like you are on top of it all, just need to spend the time auditioning your gear.
Good Luck