I've been looking for one of these interesting full coverage AM (except LW) battery/mains valve sets at an affordable price for years. There is a LW version, but rarer and more expensive.
It's rather unusual and quite severe on the battery pack, twice consumption due to having EIGHT valves!
See http://www.radiomuseum.org/r/hallicraft_s_72_s72.html
Some photos soon.
I replaced about six leaky waxies. It uses quite a few 5nF ceramic caps as couplers and has some sort of combo ceramic capacitor part on the audio out 3V4 (DL94).
I replaced one leaked, corroded LT 100uF smoothing cap into original card tube. The others reformed OK.
1T4 = DF91
1R5 = DK91
1U4 is a little like a DF92, I think, so only serious AGC on the 1T4 RF stage.
1U5 is an improved 1S5 (reduced microphonics, 1S5 is DAF91) with different connections.
Arrrgh!
It destroyed the DL94 when I connected it to the 110V AC shaver outlet. (The 3V4 in it when it came was no emission).
I'd noticed that the BFO was intermittent. It's got EIGHT battery valves in two paralleled series chains.
It was an Intermittent 0V connection on one of the two serial filament chains in parallel. That's why BFO was intermittent!
So the the two chains ended on separate tags on the main HT smoothing electrolytic and one was corroded. I've replaced wires on both "chains" to the 0V point and put them on same tag, using a single wire stripped in the middle and folded, so that can't happen again!
BFO now fine on the battery pack.
Working now on 110V Shaver adaptor.
Now to finish restoring case. Some torn bits on cloth and hinges were badly bent.
Brass front very corroded and speaker cloth filthy!
It doesn't use the 1R5 (DK91) as a mixer/osc. It uses separate valves for mixer and osc, so it's reliable to 30MHz even at end of LT life. It's got 2 x 1U4 as IF amp and a tuned RF amp (1T4) and separate valve as 455MHz local oscillator for BFO (CW or SSB).
3V4 (DL94) as single audio out, I checked grid volts as it gets warm, but was OK.
Chassis working fantastic on SW on bench with a 2m wire. Will try loop aerial on MW after dark.
All service info on web seems to be earlier version(s). I think mine is 1958.