My condolences about your dad's passing to you & yours.
A neighbor had one for sale that gave me the same idea. It was a mid 80's apache.
After multiple drawings & ideas , there was no way to cut a spear hole in it near the middle without cutting support mains & widening, framing wasn't possible unless it was taken down to the frame& re-design on the base.
Needless to say I'm still dragging a Shappell