Riveted Seat Belt Rail from Hell -- Help!
So I've started converting a 2004 Ford E450 Collins Bus and it's going relatively smooth, except one thing which I foresaw would be an issue... thought I could figure something out but upon experimenting I'm really stuck...
There are 4 seat belt rails (seatbelts bolt into them) that go down the length of the bus that have tons of rivets. I've watched various videos about various methods of removing rivets, but none can really work because the rivets sit between protruding metal bars -- I can't get an air chisel (or even a hand chisel) underneath them...
So I tried sticking a pry bar behind the metal seat belt rail after popping out the center pins in the rivets -- no luck because I can't get the pry bar behind the seat belt rail - it's too tight against the wall
Then I tried just taking my angle grinder to it -- maybe I could split it all the way down the middle? Or take off the top so I can get to the rivets with an air chisel? Possible... but when I experimented I went through an angle grinder blade in no time -- it would take dozens of blades.
I cut off the metal siding above it, took out the insulation, and of course there is structural bar behind the rail, so I can't see or get underneath that area.
So here are my questions:
1) any ideas in general how to get this thing off? I'd really prefer not to leave it on there...
2) On a related but different note -- below the seat belt rail -- is that whole metal siding the "chair rail"? It seems very tall for a chair rail. I've read not to remove it... is that true? How to I get to the insulation behind it if I don't remove it? The seat belt rail divides the regular metal siding with the chair rail, and in between the two is that solid metal structural bar that sits behind the seat belt rail. https://imgur.com/8o1HcD4