Hi Bax , I am building the GP Corsair 4u kit and so far I am faced with few problems. To start with the kit came with two sheets of the same sheet of (sw4) thus I ended up with two ribs missing and two ribs of one type extra. No problem I did manage to cut the missing ribs from a piece of a spare balsa that I had. Then the ribs were so tight to fit on main spar that I broke some while trying to place ribs 1,2 3 5. Drops of CA did cure the problem but some how when the bottom ribs R5 jigs on the end of the center spar are not touching the flat board but they are probably 1/4" above the surface. would you advise me to go on building it or break all the back ribs from the center spar(which could be a messy job) and try to tilt them so that their respective rib jigs sit on the surface? Thank you