According to the GE datasheet, the "A" means it has a grey tinted faceplate and is not aluminized. You do need the ion trap magnet.
You can see the gun is bent. It would be dead straight if it was aluminized and did not need a trap. Another check is look at the front around the edge where the phosphor ends. Is the glass transparent or shiny and mirror like?
https://frank.pocnet.net/sheets/093/1/10BP4A.pdf
You're not going to damage it in a few minutes. Turn the brightness up all the way and quicky rotate the magnet all the way around the neck. Soon as you see a glow, slow down, turn the brightness down and find the sweet spot.