Good news to share: despite cleaning up the fastener threads with a Lange kit twice, I picked up a new bolt kit and all three bolts went in like butter. It was a fastener with bad threads. It's a relief that the problem was a simple one to solve but equally frustrating that something like bad threads on one bolt can set you back hours.
I have two remaining items to tackle. The exhaust sounds like a dump truck so some adjustment is needed to get it tightened up and properly sealed.
As fate would have it, the starter just started hitting the flywheel when the truck is running so it's on the way out. A new unit arrives tomorrow.
Hopefully by noon tomorrow, it will be back on the road.
I appreciate the continuous advice and more importantly, the motivation. This job as been an epic challenge of will and determination.