If you want a light boat, make it simple and clean!
* Glue the boat together, no screws or heavy fittings to transfer the load from the beam to the hull.
* Remove the jib, and make lighter hulls since the compression of the hull is reduced.
* Without the jib you can use twin forestays and get a stiff boat.
* Use lashings for the stays and use something else than stainless wire for the stays.
* Use light sails, different materials in the sails can differ several kg! For example the MAXX sails are quite heavy since they are strong in all directions compared to "normal" cloth.
* Remove fittings and trim lines. Check the latest A-class boats from geltec, they are clean!!

If you want to go the other way you can see how the M20 was downgraded by some owners by adding a jib with bridle, stainless wires, external halyard for the spi and a big fat block system for the main sheet instead of a light caskading system, no wonder it weighed 120 kg. But which version of M20 won the texel, the original M20 of course!

/håkan