I just got my Yak-3, and my landing gear are also defective: gear doors on the wrong way, and grey while the rest of the underside is light blue. The cockpit & framing looks a little "off", too. I'm pretty disappointed in the model.
It seems to me the landing gear is frequently a weak point in IXO/Altaya and other manufacturer's models. It's nice to have a fixed-undercarriage plane like the Stuka, Gladiator and Swordfish, so it isn't even an issue. Next on my wish list, A5M Claude, Aichi Val...