Out of personal preference I try to not mix scales in excess of 10%
Using 1:350 scale parts on a 1:426 scale kit is 17.8% too big
(350 - 426) / 426 := 0.178.
Your opinion may vary, but to me the visual difference is just too jarring
500 scale is likewise too small (also about 17%) Your best bet is to use 400 scale aftermarket items. They are only 6.7& too small