If there are no voltages coming out of the transformer then it's possible the integrated thermal fuse (150 Celcius) has blown. If you're lucky then it's just underneath the first layer of the transformer. In any case you will need to determine what caused the overheating in the first place.
The DC unloaded voltage on the PM7000 is 57V. After considering the rectifier voltage drops and regulation etc, that would require 2 x 40V AC secondary. The 2 off main filter capacitors are rated at 63V DC and 15mfd IIRC. The PM7000 model I had used an EI transformer, and I would guess it was rated at about 300va, so you should be able to get a toroidal transformer wound for this at reasonable cost - make sure it will fit. Note, the PM7000 transformer has a copper band around it to reduce radiated mag fields, so if you do go down the route of getting a replacement transformer wound, make sure it has a GOSS band fitted. Stephen Foster at Tiger Toroids is a good source and a very helpful guy.
https://www.tigertoroids.co.uk/
https://www.tigertoroids.co.uk/