Well, I finally put together two AZ50 rectifiers, two 300B and two C3g tubes on the top of the 19"/2HE rack , together with PT (grey box).
I wanted compactness of the single chasis stereo amp, but you can see the inside - two PTs, four PS chokes, two grid chokes, 11 big capacitors, two CCS modules, etc. Everything is closer together then I really liked, but I tried my best to somehow put all this together. See the position and orientations of various magnetic components.
I added partition in the middle of non-magnetic steel, a little bit of separation between the channels and components, but its main purpose was to strenghten the chasis - it isn`t human how heavy is this amp!
The components are hanging upside-down, screwed on the top plate - good for servicing, but not so nice looking of many srew-heads on the top plate...personally, I don`t care.
L & R inputs are in the corners, very close to the "Goldpoint" input attenuators and driver tubes - just a few cm of silver wire...
On the first picture you can (barely) see the pot for hum balance, and a little socket for monitoring the bias current close to the 300B socket.

From the rear you can see the (IMO - nice ) location of LEDs for the C3g bias, connectors, switches and pots.

The sound is a little more "damped" and less open then breadboarded version, probably not a surprise - monobloc construction and a larger chasis have their advantages.
After a few hours of burn-in (listening the music), the sound is a bit better, but I`ll try a few things (Mu-out) again...and again...
And one more thing - I relocated the amp to the home where the mains voltage is about 5% lower then in my "workshop"(B+ and B1+, too)...output tubes now biased about -69V (it`s a 69/910 ~76mA), I`ll probably lower Rk`s a little. Expecting update in a week or two...