10 LBS???? Holy cow, that's a lead sled! With that weight and only a 76" span, I can't believe a .74 would get it off the water. Maybe the previous owner bungee launched it ;-) Sounds like it's time to take a hole saw to the sucker and start lightening (or plan on a way bigger powerplant).

Wondering now if it's a 1-off home built 'copy' of something (ala Mariner).

The intrigue continues....keep us up to speed on the investigation!

Steve