Hello all. I'm Jay Chladek and I came up with the wrap fix. It does work and looks good when done. Here are some other tidbits:
Glue for the wraps: I utilized Bob Smith Industries Finish Cure Epoxy brushed on. This is not thick like a glue. Instead this is a thinner grade, almost liquid, intended for brushing on surfaces like foam to bond wood skins to them. It works nicely for the wraps as you get decent working time and they dry nice and hard when fully cured after about 24 hours. I went a bit conservative on my first application, only using it in the centers of the wraps and thin CA to tack down the edges. But as I got more confident, I used the finish cure more and more. To help apply even pressure to the wraps while they dried, I used rubber bands.
Plastic Weld Glue: These wraps are rather thin and not all plastic weld glues will work with them effectively. I tried Ambroid Pro-Weld in one spot and it is way too hot, distorting detail way too easily. Plastruct Plastic Weld (orange bottle) seems to work nicely for the fin fairings and the fins. I can brush the stuff on for a good bond, yet it doesn't bite into the plastic wraps too hard to distort it, provided I don't touch it while it dries.
Wrap detail reinforcement: Not sure what this will do to COG issues, but with the wraps being so thin, I was afraid the large protrusions such as the ullage motors and APU fairings would get crushed if I wasn't careful. So I back filled them with two part Epoxy Putty. In my case it was Aves Apoxie Sculpt, but Milliput can work fine and it sounds like JB Weld can also be used. If and when I get around to flying mine, I will go for the bigger Estes motor as I want to make sure she doesn't get marginal in stability. The back filled fairings are nice and sturdy now and should survive what abuse I can throw at them. I also used some putty on the back edges of the fin fairings to give them some durability during construction and landing (just on the bottom edges).
Centering rings: Yes, they appear to be a hair too small and slide a bit loosely in the body tube. Not a deal breaker though when glued in properly. But, I found the wood glue I used on the rings as it dried caused the outside of the body tube to shrink where the glue joints were. So it does require a bit of filler on the tube to get things leveled off. My primers of choice are Tamiya brand spray and liquid primers. I use the standard gray primer for filling the body tube wraps (with brush applications of liquid primer to build up in the deep spots) and will use Fine White primer over the body and the wraps to help prep the surface for painting. Tamiya primer is designed for plastic models and although it is a lacquer, it should not be hot enough to attack the wraps, provided you don't layer on way too much during a spray session.
The wrap modification: Others have already talked about the modification I came up with. When I found the flaw on my rocket, I immediately informed Estes, suggesting they post an addendum fix for the instructions. At least it sounds like they are mentioning it in conversations with customers. That is a good thing. I doubt they will fix the wraps as plastic molds can be expensive. But if you make the cuts and center everything from the S-II/S-IC interstage ring on down in regards to details that line up with the gantry swing arm umbilicals, the fix works. Based on what I can see, this Estes kit is the most accurate Saturn V kit out there in regards to exterior details. It is even more accurate than most plastic models with the exception of the oversized fins for flight.
Now those looking for additional references on the wrap details and paint patterns can look at the following site for reference:
https://apollomaniacs.com/apollo/saturnv_menu_e.htm
All major Saturn V details were the same on all the rockets. Nothing changed position as the gantry swing arms had to attach to the rockets in the same spots. Apollos 4 and 6 had 8 ullage motors, 9 through 14 had 4 and Apollos 15 through Skylab had no ullage motors on the interstage ring.
I'll post images of my work once I have figured out the file uploads.