Hi Alan. See if this post from last year helps :-
https://www.vintage-radio.net/forum/...d.php?t=150270
The speaker outputs appear to be twin red for left and twin black for right. There should be a marker on the wires (usually a line ) to show which is + and - .
The other wires will be positive and earth. It's advisable to check which battery polarity the unit is set for as in the instructions for changing it.
David.