I mention three gaps... the ones I think you are questioning are the gaps that are created in the horiz stab slot top-right and bottom-left. They were probably over 1/16" wide, and yes, due to the shimming necessary to get the stab parallel to the main wing. They were way too big to bridge with the thick CA. I wanted to epoxy it in, but there is no way to get that goo in there without messing up the finish. We made small 1/4" wide tapered shims going in the front and rear, top and bottom to balance the offset. In retrospect, some carefully carved shims that extended the entire length of the gap would be better to fill the gap. I wasn't that patient. But, there would still be a visible stipe without covering. I pushed the shims in until they were forcing the parallel condition, then shaved off the excess flush to the fuse. It turned out pretty good. I pulled and jerked on the stab, it's definitly there for good.

"We"... I am doing most of the build, but this plane belongs to my father-in-law. We are working on it together. It's a family obsession.

The photo here shows the big tapering gaps with the elevator and fillers. They are big, and uneven... I don't know about you guys, but I want the filler to elevator gaps parallel and uniform. I doubt it would hurt the plane's performance to leave it, but not much pride there. You can see the silicone sealing of the stab joint here too. Turned out pretty good. I filled the pin holes with the silicone too, they disappear!