It's all about valves

With the schematic in hand, we can see that this amp has seven (count 'em) valves or "tubes" as our American cousins call them.

If you want to learn about the different types of valve this is a great site.

The pre-amp valves are two 5879s. The phase inverter is as 12AX7. There are two power valves which are 6V6GTs, a rectifier which is a 5Y3GT. Last but not least is a 6SQ7 valve which is used in the tremelo circuit.

Now we need to get hold of the specifications/data sheets for these valves. The best resource I have found is at the Tube Data Sheet Locator (TDSL).

From this we learn:

5879: This is a pentode valve that uses a 9 pin noval B9A socket. It requires a heater circuit of 6.3v. It has a plate current of 5.5 mA.

12AX7: This a triode valve that uses a 9 pin noval B9A socket. It requires a heater circuit of 6.3v. It has a plate current of 1.2 mA

6V6GT: This is a tetrode vale that uses an 8 pin octal socket. It requires a heater circuit of 6.3v. It has a plate current of 47 mA. Because it is the output valve we need to note its output inductance which is 8000 ohms with a two valve output stage (this is relevant to the selection of the output transformer).

5y3GT: This rectifier uses an 8 pin octal socket. It requires a heater circuit of 5v. It outputs 125 mA of DC.

6SQ7: THis valve uses an 8 pin octal socket. it requires a heater circuit of 6.3v. It has a plate current of 1.1 mA.

I sourced two NOS 5879 from ebay for £10.
I got the 6V6GTs, the 5y3GT and the 12AX7 new from Hot Rox
The 6SQ7 was harder to find but I got one from watford valves.

From all of this we can see that we will need:

3 Noval B9A sockets

4 Octal Sockets