While in-there, what I found on the pumps. The early Mopar pump motors have a special wiring with two fields, one for each direction, and both flowing to ground (need to run ground wire to motor frame). The under-dash switch, energizes either the red or yellow wire for raise and lower (or vice-versa, check manual). You can still buy the pump-motor, but ~$350.
An alternative is to use a later pump-motor. I used one for a 1990's Ford Mustang, used on ebay ~$701 (yes, many Mustangs get totaled). Externally, they look identical, the rubber mounts are the same pattern, just the wiring changed. They have a single coil and reverse polarity to raise or lower. I rigged 2 Bosch relays (5-terminal) underdash, operated by the factory switch (wire both NO & NC terminals in X-pattern, you'll figure it out). The relay outputs apply 12 VDC to the thick red and yellow wires going to the motor, with alternate polarities. Advantages are that I can use a cheaper/available pump-motor in the future (not just Ford, probably Sebring, ...) and my factory switch now carries almost no current so won't melt. Newish Mustangs also use such relays, but mounted at the motor. If you leveraged their relays, you would need to repurpose the red & yellow wires to provide steady power (one or both), plus run new (thin) wires for logic control, so easier in our cars to have the relays at the dash.
The later motor might give more power since you are using all the coil, not just half a coil in each direction. But if the motor is straining, the problem may be in corroded cylinders or frame pivots. The cylinder rods in my 1964 Valiant were bent as-found, and the pistons stuck in the cylinders from corrosion. But, new cylinders are available and affordable ($220/pair, I recall).
