Deon,

My son has been flying his for nearly 18 months not had any problems with the build or the flying. If you make a small stud with a sharp point, to fit into the hole on the wing root rib (dowel location), then slide the wing on to the wing tube and line up with the reference points on the fus then press the wing firmly against the fus, the stud will leave a small dent and this is your dowel location. With regard to the fin, cant comment with out a photo. I found the instructions more than adequate, rarely had to refer to them.

This is the link for the forum in the UK http://www.rcmf.co.uk/4um/index.php/topic,14319.0.html