STOP THE PRESSES!!
Some really great suggestions here, but the problem was solved in a really funny way. In fact, A-Ron actually found the problem hours before I did:
I called our chapter tech counselor because A) he's smart and B) he's building an RV-10 like me, but I'm a few years ahead on build. The conversation went like this (abbreviated for effect):
Me: "Ken, check page 11-3. How would you do this with this bushing thing? A #17 is too big, the bushing only takes a #30."
Him: "Match drill #30 thru the bushing."
Me: "No Ken, it says match drill #17."
Him: "What version of the plans do you have?"
Me: "Version Zero, why?" **ZOT!!!**
Version 0 of the RV-10 has a typo and calls for #17 drill on 11-3 Step 2. As A-Ron pointed out, it's really a #30, as corrected in Version 1.
Thanks All, I shall keep these things in mind and ponder them as needed...