Scott
That's interesting. Did it look like a retrofit or a factory job? I have heard that there is a small tube at the aft end the spreader bracket attachment point that is welded at the factory into the section.
I also heard that one of the problems is that this was apparently not enough reinformcement...because the front of the bracket tends to pull away from the mast --
- maybe your in your instance the 1" bar retrofit solution (if that is what it is) is that by providing a larger, stronger more rigid compression point at the back --- it is enough to prevent this flexing.
I can't imagine once you bore a 1" hole on each side of the mast at the aft end of the bracket that you would even consider cutting more away further forward for a thru-bar.
So your mast is basically done...no thru bar potential here unless you weld a patch or sleave to cover the 1" holes.
I guess one has to take the brackets off to know fully what they are dealing with ...thanks.