I do not claim to be an expert on fiberglass work or know the exact method to install these, but I will certainly share my experience with them. I have mixed feelings about them since going through the installation process when I restored B034. One of the wingtips on that airframe was crushed and the fiberglass option made sense to me beacuse I didn't want to try and bend up the tubing for the wingtip. I was fairly certaint that I couldn't make a mirror copy of the opposite wing. On my next restoration I will not be using them. I feel that using polyfiber will be lighter and have plenty of durability.
If you have the trailing edge mod then the glass wingtips will need considerable work to blend the trailing edges to match them up. It was labor intensive, but really made them look like they fit nice. The d-cells needed to be trimmed where the leading edge tube of the wingtip assembly riveted on. That was required because the glass wingtip would not slide over that area. It's hard to describe, but very obvious when you go to slide them on. You'll see a fair number of rivets, mostly because they were needed to keep the fiberglass work flush to the aluminum. Be aware that, in my case, that the wingtips were too wide at the leading and trailing edges. I used a dremel tool split them at the seam and then to eat out the extra material until they fit nicely. I then layered glass on the inside for a strong bond. I just filled the outside with fiberglass epoxy and then sanded it smooth. Hopefully these pics will help. Again, this was how I did it, if anyone else has input, please share.
Dave