Gringo,
I'm struggling with the idea of mounting my landing gear too. Did you use the stock gear or a replacement? I'm bought the B.J. vented 60-80 sized gear. (
http://www2.towerhobbies.com/cgi-bin...?&I=LXCFR7&P=7)
I am not going to mount mine thru the slots in the side of the fuselage. I'll ply over the box where your screws come out and mount the gear completely externally. I'm thinking of splitting the gear and using 2 nylon bolts on each side, going into pine blocks underneath for a tear away gear. This gear is about 1/2" short on each side, maybe slightly less than that. I can extend it if I cut it in two. It will look much better than the heavy gear that came with the kit.
It looks like you could tap another blind nut on each side without too much problem.