Looks like a great tool, Ben!
How to hold T-track on its side to fit the groove in the die will take some experimenting.
Maybe hardwood filler strips will work.
Or machine-shop altered rollers (cutting in a deep groove on one side of the appropriate (2)die channels) that'll track the wings of the T.
Or a two part jig attached to the bending machine that holds and feeds the T-track on edge going in and coming out.
Again with woodstrips to guide the track in the channel of the roller die while it's bending. Mild bending, but a lot of pressure.
It would indeed be great to prebend the track so that it can be placed onto the rail without dislodging the butyl tape.
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It'll be difficult.
Reassembling straight track that requires that hardwood jig, mentioned above, to get it to curve
means that some method is needed to hold the bend over the the toerail with the caulking tape attached
(either to the rail OR the track) AND lowering it without scuffing the tape out of place.
To me that means some kind of temporary longer straight round rod inserted probably in each or every other drilled bolt hole
just to guide track & caulk to locate correctly for the fasteners.
It is important for butyl to get compressed into every chamfer. So some measure of finesse is going to be needed.
Haven't thought this move through yet!