I had a '60s Bally that had a funky metal bar for the lift bar (looked like someone just made it himself) that I had to get off. It looks like it had some epoxy glue - not friction tape! I had 2 backboxes having around, so I put them about a half inch or so away from each other with a bunch of bubble wrap and towels draped between the backboxes, and then seated the backglass bottom bracket along the edge of one of the backboxes, and then just let it sit - for a year! It didn't fall off, but the adhesion did degrade so that I was able to take the lift bar off with a little pull.