My P19 #352 is set up the same way, and I must warn you that supporting the
weight of the entire board on those 2 pins sitting on the trunk will
eventually gouge out divots under each pin. May I suggest you get a couple
of lengths of wood (oak?) about 1/2 inch by 1 inch that you can sit atop
the trunk on either side of the board, possibly held in place by some sort
of quick-release wing-nut arrangement at the fore and aft ends of the
trunk. Then you can drop the board so that the pins rest on the wood
strips. This well distrubute the weight evenly across the trunk, avoiding
divots, and when the wood wears out, it is a simple matter to replace it. I
also try to let the cable bear a bit of the weight.
Tom
P19 #352 Windsong
Whidbey Island, WA