unfortunately there won't be much you can do about the compression issue, if the cylinders/piston rings are worn and/or valves not sealing good that would be quite a bit more work to fix. Resleeving and re-ringing pistons, headwork, etc.
A reman engine would be a better option versus all that work.
As for the fuel pressure, if the pump is bad it might could be rebuilt or just replace it with a reman one (or new depending if there is even a reman available).
The grid heater might gain some advantage helping it start easier but wouldn't work as well as a cold start kit (ether).
If there is a cold start option for it that might work better, ether always starts an engine quicker. There may be an aftermarket kit you can get for it if one isn't available from the mfg.
Just remember, with an old engine like that hitting it too hard with ether can be bad for it, but then again that goes for even a new engine. Ether lock up is hard on them and can break things if you're not careful.

The thing about the grid heater, if your environment is already somewhat normal (not cold) i'm not sure how much advantage you would get since the air going into the intake is already somewhat warm? The advantage may not be as good as you want.