This Montgomery Ward 62 GVC 9033A guitar amp was made by Valco.

The amp has two channels, each having a Volume and a Tone control.

Channel 2 also has a Tremolo effect with Speed and Intensity controls and a Footswitch jack.

For output, the amp uses a pair of 9-pin 6973 miniature beam power tubes.

There are also three 12AX7 tubes (two for the preamps and one for the tremolo) and a 5Y3 tube rectifier.

Disassembly of the amp is easy:

First, unsolder the two speaker wires seen here.

The green wire connects to the speaker "+" terminal and the black wire connects to the "–" terminal.

Then remove the two chassis screws on each side of the speaker cabinet.

Here, the Valco amp chassis is out of the cabinet.

Pull out the two 6973 tubes before starting work on their sockets.

Set the chassis on wood blocks, as seen here, so it's steady and its preamp tubes are protected.

Here's a close-up of the wiring side of the 6973 power tube sockets, left and right.

We want to change the wiring of these two sockets so they're compatible with either 6973 or 6CZ5 vacuum tubes.