[Arran]

Most loctal tubes have the number etched into the glass on the top, ether inside an octagon or just the number by itself, the part that will wipe off with water is the label on the side. You can often tell what they are by looking at the elements on the inside, a, XXL, for example, is a stand alone triode, so the plate is rather small compared to something like a 7A8, a 7B5 would be in-between, and the plate would be roughly oval shaped. An Ohm meter should be able to tell you the continuity, the heater on a 7B5 is pins 1 and 8, cathode is pin 7, an XXL or 7A4 would be the same. There should be a pair of XXL/7A4 tubes next to the tuning capacitor, one is the oscillator, the other the mixer. The IF amplifier tubes are 7B7s, so those would go between the IF transformers. The first audio tube is a 7C6, and that goes in the socket closest to the front of the chassis, you can tell that apart from the XXL/7A4s by the fact it's got a rectangular box shaped structure bellow the triode plate, those are the diode sections. One issue that many of these tubes have is intermittent contact between the tube pins, and the socket contacts, so cleaning the sockets, and pins is a good idea.
Regards
Arran

I think you may have seen this but here it is again https://philcoradio.com/library/download...20Book.pdf