Rivets in plans
If you haven't already done so, have a look at the RV14 wiki done by Halpilot (I think that is what he goes by on here, very active in the RV14 section)
The wiki, if I remember correctly says people have found success with a different sized rivet than what is in the plans. I can't remember if bigger or smaller but I do remember doing this step and not liking the result with the rivet in the plans. Then checked the wiki and used the size others suggested and came out perfectly.
Possibly it was a diferent revision to current plans, YMMV etc.
If you're building a 14 that Wiki is an amazing resource and totally free. Big thanks to Halpilot!