Yea, I took my calipers to the glass and channel yesterday and came up with a .040 difference per side... a bit more than 1/32 (.032). But I'm not going to over-think this. It's a piece of glass that has to fit into a frame and be held there until I die or sell the truck, which isn't going to be any time soon... I hope. I have absolutely no compulsion against building up the entire assembly and then gluing the glass in with silicone. Working with a built up assembly I'll be able to precisely align the glass... this is not rocket science.
Also... the tape I bought was specifically sold as being correct for the vent glass in my truck. IMO, they should just sell this stuff by thickness, rather than application.
And I'm not spending a bunch of money on rolls of different thickness tape just to get 3 feet of what I need. There's just so much time and money something is worth and I've reached the point of diminishing returns long ago on these vent windows. This is a driver, not a VCCA restoration.