My engineer cousin says the Buna is better for this application too. As for the hinge bolts maybe my body is off a bit but there was no way the cylinders were coming in or out without grinding a bit off the ends. I don't think the cylinders will miss 1/16" of support. Both sides the quarter glass was down in the cavity so I took them out and fixed them. Today I put the quarter windows back in. On both sides the little wheels at the bottom that slide in the track were busted off. Re-pop to the rescue. There is a special tool to screw the threaded retainer washer. I was able to get them loose with a big water pump pliers then I used a snap ring expander tool to un-screw and re-screw. I am anal about lubrication and I added a drop of Tenacious oil on each wheel shaft. Serious bike riders will know about Phil Wood Tenacious Oil. As the name implies it stays in place and doesn't attract dirt. Then I adjusted the windows to the top. The screw-bolts are used for this. I gave them a squirt of paint so I could re-locate the nuts easier. I tried to get the glass as centered as I could in the opening and fitting flush with the top.