tomd-RCU
As for your problem, I would guess that you will either have to add or delete something on either the tips or wing end to get a perfect match. And that will result in some rework of the covering or paint. If the tips are sticking up above the wing, you might try cutting a small triangle shaped slice out of the middle of the bulge, and pull in and glue the sides. Maybe you can heat the plastic tip and reform it to fit – BUT this could be a disaster if not done carefully.

I am currently framing up the wings, with all bottom sheeting and internal stuff in place. Here's some of the things I am doing that's not called for in the instructions. Wings will be plug in with internal wing tubes out to the sixth rib. Wings will be sheeted top/bottom with 1/16" balsa. Wing tips will be built up from balsa. Flap and aileron servos will be mounted in the wings, with tubes installed for the servo extensions. Ribs adjacent to each servo bay are 1/8” ply. Cabin area of the fuselage is built with 1/8" light ply sides, with internal scale structures and full instrument panel. Fuselage from rear of cabin back will be built as a separate unit and attached to cabin area. Depending on weight, I may sheet the rear fuselage. The problem with a Beaver is it’s very short nose, which can cause all kinds of balance problems.

The firewall supplied with the kit does not match the plan dimensions, so I called Unionville - who said they have reduced it to provide more air flow between the cowl and firewall. I will probably build a new cowl. On the plan provided, I found that the left/right spans of the stabilizer/elevator are not symmetrical.

Good luck with the fixes.