i get it, like you said nobody needs to know what your gonna do with the parts and even so what are you going to do build a bomb? crazy days.
your bang on, its a one way flow control. on the model 20s they rarely fail.
you should know they are designed for a load on the forks of 3000lbs, they come down rather fast unloaded. downdrift is going to be your enemy after your on the second floor for a couple of hours with the model 20's hydraulics. they all downdrift somewhat. your going to have to build a new hydraulic system for this to be a success i don't see how you can make it useable with the current manual spool system. i would want a solenoid system with controls on the house walls upstairs, downstairs and on the car. you got your hands full here.