Step one:
I drilled a hole through each bow then refilled that with epoxy. The hole i drilled was about 3/4 of an inch and then once the epoxy hardened I redrilled a 1/2 inch hole. This was to make sure I was drilling into solid hull. You can see in the picture above that I ran a piece of non stretch line through the hole and tied a figure 8 knot on the outside and a loop on the inside. this give me something solid to attach the bridle wires that support the spin pole to.
You can also see that I have bridles that run to where the bridle wires attach. This supports the middle of the pole.
In the picture above I have no prebend in the pole but I now run with about 3 inch's of prebend in the pole that I pull into it using a truckers hitch on the two bridle lines up front.
To support the pole vertically I have a loop of low stretch line tied around the connection of the bridles and the forestay. there is also a metal support that i made out of 1/4 inch stainless cable just like your shrouds would be made of but it was a pain.