When I had a look at the ramp on the landing craft at the museum at Birkenhead (now sadly no more since the accursed development yuppies bought the site) it had a single line, fixed to the hull port side, across the ramp and led back to the winch. It would drop under gravity.
The same arrangement should be OK using a small servo converted into a winch. Limit switches are not needed- just stop raising when its fully up. Alternatively, an unconverted servo will do the job with a push-pull linkage, just relying on your touch on the control to set the speed of raising/lowering.