John, on my H-18 I ran my spinnaker sheets to the shrouds, back up to blocks on the front crossbar (just inside the hulls) and then back to the center on the rear crossbar. (a big M) I have a front pole snuffer.
Haylard line runs thru the spreader down to a block & spinlock cleat mounted on the front crossbar about 4" off center of mast. The haylard line runs from the top of the crossbar back to center of tramp then under the tramp back to a block on the rear cross bar, then to the snuffer bag.
I would share pictures but one hull is in the basement & the other is in the garage.
Also, Check out the F-18 website for ideas.