I finally sailed my Nacra 5.0, I will put a sort of report, with my impressions and some questions here, thanks for listening..
From the original owner I bought the hulls, correctly assembled witht the crossbars, the trailer, the jib, the front stay, the rudders castings (home made by himself, but fairly good), the mainsheet traveler and the ball of the mast.
I repaired the trampoline, and navigated for a while on the web, where I could buy the mainsail, the rudders and the blocks. Then I got a package with rigging cables, traps, harness and other stuff, mainly from a hobbie 16 (everything used and cheap, of course). I had to extend some of the cables. The hardest was to get the mast, I finally got an extrusion and made all the parts on local workshops. The base of the mast is basically a plate with the shape of the mast, with soldered pieces above, to fit on the inside part of the mast. Below, a cilindrical piece soldered to the base, with a semi sheric perforation to fit the ball of the mast. No pins. It works pretty good, I can´t start raising the mast horizontally but about 30° or so, it´s not a problem, and it´s not necessary to raised it rotated 90°, which is an advantage. I put this cilinder in the front part of the base, so the ball is in a very advanced position, I think more than in the original design, I wasn´t very sure of that... To my surprise, it worked excelent. It alwats takes the same angle than the sail. Much better than a Nacra 5.8 that I sailed once, where the mast was always rotated 90°, no matter what. I might have displaced the sail area a bit aft though..
The only thing that bothers me is that I look at the jib and it seems quite small, it might be from a smaller cat, this and what I mentioned about the mast made a surface area not very balanced, the tiller requires some force to keep the direction.
The wind was quite strong, but I never got to raise a hull completely, I prefered to do some trapeze work instead, I feared that the tip would sink and I would capsize. I will go step by step.. I´m interested on opinions about this, perhaps this cat is not very good on raising a hull.
Thanks