Salty Dog did my modifications back in the 80's, but they took the existing tramp and just moved the existing socks that the tubes ran through. I don't know if they took a pattern from them...I just told them where I wanted the socks to be moved to. I am sure any trampoline maker could make up a set from your own drawing. Any deviation from ideal can be taken up by the lacing down the center of the tramp.

For my N5.5U that I was buying a replacement trampoline for, I purchased a bias-cut trampoline from Salty Dog. This one eliminated the need for any lacing except at the rear, which made for a really nice trampoline. By the patterns being cut on the bias, when you tensioned the tramp at the rear, it also tightened the sides. No longer any need to go through all that tightening of the center lacing from underneath the boat and the end result was really sweet! The reason most companies don't do this is that the material from which the trampolines are made make it more difficult to get the bias-cut tramps out of the roll...just more material required from the roll to get the end item.

If I were designing a trampoline that slotted into the hulls and front beam, having a separate strip at the rear, I would go bias-cut and eliminate the cost of adding all those grommets and line for center lacing. It seems all the new boats lace to the hulls and rear beam strip. This sure eliminates the problems of pulling bolt ropes out of the slots in the hulls and makes the molding of hulls less complex and with less material. It is probably the right direction to go.