there are some comments taken by a gavia u-2 step by step build guide, taken from a greek magazine.
1. take care at wing upper lower and mid section assembly.
2. take care of the non existent locating pins.
3.Wing struts have problems of alignement.
4. the builder used scratched built landing legs.
5. take care of the wheel(tyre halves)
6.clear dont fit well, same for PE windshield
refs
www.jiop.fi/ksimuseo/p_u2.html
www.ctrl_c;iu.se/misc/ram/u-2html
magazine is late 2001 so dont know about site connection.
best of luck.