There are two versions of this portable record player, the mains only one with a UL84 and UY85 and the more common one with battery/mains operation and a transistor amplifier. This was the latter.
First the power supply: The mains input socket was designed to operate a little switch to switch from battery to mains but it depended on having the original mains cable which I didn't have. The solution was to use a small relay as per the diagram attached. The relay was wired so that without mains applied, the battery would power the amplifier. When mains is applied the relay was energised and the relay would switch to power from the transformer and rectifier.
The relay switches on the negative side purely because it is a positive earth system, it wouldn't have made any difference if I'd switched the positive side, however the motor and amplifier are switched on the positive (ground) side because I used the motor switch to switch both amplifier and motor and that switch is on the positive rail.
Next the deck some of the problems were discussed in
this thread But there was more to it than that. One of the problems I found was that other springs were also missing. One problem I had was that when the last record was finished (or there wasn't a record on the stacker) as the change cycle started the deck would switch off. This was due to a spring missing between the start/stop/reject lever and a peg.
Once this was sorted out the deck ran well. The motor was adjusted for the correct speed.
The volume control was very scratchy and no amount of switch cleaner helped so I replaced it. On playing records the sound was very distorted, the cause was the loudspeaker. I found a good replacement and that cured that. Before doing so, I tried a more modern replacement, which worked but with much reduced volume. I guess they're not as efficient as the old ones.
It's now playing Whispering Grass by The Ink Spots.