@ endecotp ... thank you for bringing those regs to my attention. It would appear that, if I keep the speed of the lift down to .15m/s, then none of those rules apply - I have no problem complying with that requirement.
@ Lower ... there will be 2 wires, each with a breaking strain > 2,500kg - what are the chances of both snapping simultaneously?
The discussion strayed from the topic somewhat but, re the lift, bear in mind that this is a simple, lightweight device to raise and lower a small load a short distance a few times a day - one needs to keep a sense of proportion!