In reply to Reach>Talent:
Might not work for your bigger volumes, I thread a couple of 4-5mm cord through two bolt holes and us that to lift the volume, once screwed in place, untie and pull out (have one for redundancy if your concerned). The T nut issue - if you are happy to swing yourself off it once fixed in place, then surely it'd take the weight of the volume being hoisted? I assume the volume will weigh less than 13-14 stone? (not a direct guess at your weight there MK)
kev.