I have a question. ......snip My opinion on spar holes. The dowel solution is fine in a the compression zone but only increases stability in a tension zone. My opinion is to to make every effort to reuse existing holes. If that cannot be done, dowel plug all holes and move outward on the spar (I don't know how far but 6 diameters would be a good guess) and install the bracket with the new holes in the same plane as the plugged holes. My thinking here is that no matter what you do with the old holes the area of that section is gone. Moving outward reduces the inflight moment at the section of the new hole and the spar is no weaker than it was with the bracket in it's original location. The farther the new holes are from the original, the less important is is that they are in the same plane. Keep in mind though, the farther out the gear attachment is the more landing moment on the spar so the original holes do weaken the spar in that case. The doubler method is a good solution also but development distance, grain direction, and transferring the tension loads through the cross grain sections of the web are important considerations. The KR is a strong little plane and I wouldn't spend a lot of time worrying about it, just put the bracket where it needs to be and have fun building.
Pete Gauthier KR builder Woodburn, OR
