Thanks Alex,
the theoretical model was made by my 5yo daughter
Dad dreamed up the cradle/strap idea 25 years ago.
2 large brass knurled knobs help tighten the straps.
Nice and firm ....no creaks or shifting weight or freefalling
OTAs!
Another idea is the over centre clamp idea like on 10 litre
paint tins....but if you bumped that type of clip in the dark
you could be in for a huge crash.
Steve