It took a little searching but I found the appropriate temporary bolts and hardware to attach the spar carry through bulkheads together at Lowes. They were quite expensive but fit well. The smaller bolts were a little too long and needed extra washers. The spacers themselves are a little warped so I made sure the convex sides were facing out in each group of spacers. This makes them difficult to get between the bulkheads but once you get them lined up the bolts draw them down for a proper fit. I left blue painters tape on the outside spacer face that touches the bulkhead.
