here is an update of the latest status and some observations I want to share with the community:
1) The lower eye of the bowden cable (there were the cable will be attached to the lower B-pillar) is to small. The screw that is assembled at that position on my 2001 Boxster S has a diameter of 5.1mm. Whereas the eye just has a diameter of 4.9mm.
It took me just some minutes to widen it by a Dremel tool. But if somebody wants to buy a GAHH top, you might ask them if they changed this glitch. I already wrote them a mail regarding this.
Also the length of the outer cover of the bowden-cable was to long at that position. I was not able to align the hole of the eye with the hole were the screw has to go in. So I removed about 1 cm of cable cover to give the eye more play. With that the assembly was no problem.
For me it looks as if they ship the top with the wrong eye, which causes both problems.
2) There is no hole in the canvas flap that will be attched to the lower B-pillar (described in 1) ). Punch a whole large enough before you install the top. Mine was very small ( I did not want to remove much material). So when I had the top on, it was very difficult to widen the hole up as the flap is in a very narrow place between al those bows. And it is anyhow a difficult location when you try to align the screw with the eye and the washer and the flap to the hole. Finding a dropped parts would be really difficult.
3) When you put the fat weather strip in the rearmost bow (#16 at Mike Fockes description) it helped me a lot to unclip those big black plastic covers that protect the hinges
4) Aligning the holes of the canvas with the holes of the aluminum plates: Due to the double side tape I wanted the first attempt of alignment being the final one. So I used long, thick toothpicks to align all holes one after another. It worked out pretty good.
5)The 4 Philips screws (#3 at Mike Focke) have a different length. The third screw from the front was shorter.
6) At the front end of the top there was a cardboard strip sewn in at the old top. The GAHH has nothing there. There was just a loose cardbord strip send with the top. I assume GAHH send this so you can kind of "fill" the metal ridge of the foremost bow. I did not use the cardboard because I could not see any help in it. Instead I used my automotive foam double side tape to fill the ridge and glue the canvas to underneath the front frame . So far it looks as if it is working pretty well.
Today I could finish my car. After everything was assembled I closed the top. Because of the new canvas it stayed about 2 inch open. So I had to pull it until the hook could engage. Now I will let it sit for two days to stretch before I try to open it for the first time completely. Maurice, do you think this time is sufficient?
I will keep you updated.
Overall I have a very good impression of the quality of the GAHH top. I mainly choosed it over the Robbins because they are longer in the market. And so the might have more time and feedback to improve their product (delaminating glass...)
Overall it took me about 4-5 hours of disassembly and about 14 hours to assemble it back together. The most time consuming part was to put in back the screw at the back lower side of the clamp rail. Both sides took me about 2 hours together. Also putting in all the weather strips into the rear end took quite some time.
The car is really looking good with the new top. So far, there is only one small wrinkle which does not bother me at all. The whole thing cost me about a weekend of time but was definitely worth the fun.
Maurice, thank you very much for all your advice you gave me. Without you advice and the Homepage of Mike Focke I would have definitely not been able to change the top myself. It is great to have guys like you out there! Thank you!
@986fan: As mentioned, my overall impression of the GAHH is pretty good. The small eye can be fixed as can the bowden cable cover. The cardboard not sewn to the front of the canvas was no big problem for me at the moment as I did not use it ( I hope it will stay this in the future). I do not know if the Robbins tops come in the same condition or they do not have those glitches. I do not know anything about the BAS top. For me the most important point was that I did not hear about a GAHH with delaminating glass after they did their improvements.
Whenever you have some questions were I can help you, please let me know.