Help! Windshield Seal Leaking

[72blue]

Well, this is a 72, everything is new; windshield, rubber, paint, etc. I am using the original trim though. I normally keep her inside and out of the weather, but she is at the body shop getting a fuel door installed and a few touch ups here and there and BAM, its gonna be a rainy week. I went down to see how the seal is holding up and sure as heck, a pool in the dash. I bought all my seals from Steele and the glass installer would not use any other seal but the ones he is familiar with (also so they can sell you a seal and make some more $)...I used theirs of course and now a leak. The installer says they will stand behind their work, but I am wondering if I should force them to use my Steele windshield seal or risk it with the seal they want to use. The installer also says that the 67-72 model of truck is hard to get to seal properly with trim, but if I had a 59 el camino, all of the sudden that would be hard to seal properly as well.
What brand do you guys recommend? Anyone have good luck with a particular company? I was told that Steele is one of the best. I am willing to not use the trim at all if it will help, however, these trucks came new with it and they didn't leak to my knowledge. Someone help and give me good advise please.
Here is a pic of one of the other things that is getting changed. Hope you guys like it.
Thanks
James