1989 MCI 102AW3 - Mystery Cable in Window Post

[TedH]

I am in the process of replacing three windows per side (6 total) with aluminum panels.  While installing the horizontal supports to ensure the bus doesn't make 'oil canning' noise from the panels flexing, I found a solid metal cable in a metal sheath welded and in place of the SECOND window post from the right rear of bus.  I found it when I tried drilling 1/4" holes in the posts to attach the supports (see attached).  The cable won't move and I note that the PO cut it off where it comes out near floor level.  Not sure if it is some sort of grounding cable or served other purpose when the bus was seated.  I am considering indenting OR cutting it in half using a drift as I don't want to ruin the metal in the post it is embedded; just need enough room for the hardware to attach the supports. 

Any advice?

NOTE:  When I attached, the photo rotated.  Not sure what is up with that...

[lvmci]

Gable on top of the window, looks to be the marker clearance light that would have been hidden and mounted inside the overhead bins, lvmci...