One trick you can do with torroids is to wind about 30 to 40 turns of the same gauge wire over the top of what is already there.
Switch on and test this winding and you will get around 10 to 18 volts, depends on number of turns.
Now if you connect this to the ends of your original winding then rectify you will get either 82.5 volts plus the extra or minus depending on how you connect the extra coil up.

You then need to play around with the number of turns to get what you need, it can be worked out by voltage divided by number of turns.

Also very handy to get an extra 5 v or 12 v supply for logic circuits out of a stock transformer.

Once tested a few turns of fabric tape around the torroid will tidy it up fine.

John S.