The electric pump might have stopped from an electrical fault, or more likely, from being incompatible with ethanol in gasoline. Ethanol took out TWO expensive in-tank fuel pumps in my Jeep in a couple of months before I found out there was (hidden, not disclosed) ethanol in all regular gasoline sold here, as of a short while ago. The symptoms were gradually increasing hesitation on acceleration and being harder to start--the pressure was falling due to ethanol-caused wear.
Ethanol is also a solvent, and use will dislodge crud and varnish which will possible plugging filters, needle and seat, and carb jets. But it sounds like you need a new electric pump, and to re-do your mechanical pump with parts that aren't susceptible to ethanol. Hint--never let your car sit for a week or more with the new gasoline, without running it. (Better to let it run dry before storing over winter if you do that.) Sitting too long with new gas causes all sorts of problems, and even stabilizing agents cause problems if the concentration is too high. In Spring, run through a tank of gas if you use a stabilizer and then run through another tank of fresh gas--take your car for a good long run
For my Kaiser and Studebakers, I have to run premium gas here, as it is 0% ethanol, mid is 5%, and regular is 10%. I noticed an immediate change in the power and driveability (as well as the mileage!) of my 88 Jeep and my other old cars.
As far as the low compression, further use and oil changes and MMO should help that. My Studebaker Wagonaire when I first got it would barely start, had low power, and blew solid blue smoke out both exhaust pipes, and leaked oil like a sieve. Previous owner hadn't used it much. Gentle long drives of well over an hour at highway speeds and lots of oil changes and additions to the gasoline of MMO, sorted that out over time--no oil burning, more power, starts easily.
