Removing front center wrap piece

[blickcd]

I've exposed the forward frame for cleaning, painting, etc. Belly skin and wraps are off from axles to the hitch. It's a 1979.

One piece has yet to come off. This is the front center wrap section between the A-frame. Top corners are tucked under the bottom exterior flanges of the battery boxes and seem to be jamming it up. Have drilled out the bottom rivet flanges on the battery boxes to maybe give some play but no luck.

Do the battery boxes have to be loosened all the way, or is there any other trick to getting this one piece out?

Worst case I could leave it in place but I would like to paint both sides of the front hold down plate, which it conceals.

Thanks in advance.