After various methods of comparison between the right side, which went together fine, and the left side that was troubling me, I discovered one error: The parking brake 'spreader bar' was installed upside down - pushing the shoes out and likely preventing me from installing the drum and having a freely rotating wheel. I set about pulling the brakes apart and flipping the spreader bar around to the proper orientation. With that done, I again attempted to install the drum...no dice.
Took it all apart again and replaced the adjusting stars while I was checking that I'd oriented the adjusting screws correctly. No issues so I can add those to the slowly growing list of 'what it's not'.
The only other semi-logical thing to do was to remove, one by one, the new parts and replace them with the old parts until things fit again. So, for the fourth time in 90 minutes, I was taking it all apart again. If swapping the old part with the new part didn't resolve the issue, I put it back on...you know, just to complicate things a bit.
After fifteen minutes of swapping parts, I found the culprit: The new spreader bars were 6mm longer, both externally and at the contact points for the brake shoes and lever arm. The old spreaders are a little beat up but they still work. I swapped both new spreader bars with their old counterpart and both sides went right back together.
Unfortunately, I've way over-scheduled my activities for the day so I had to stop after it all fit back together to do what I'd originally planned for the day.
Photo from the workshop manual that I had open while I was working on the car...yeah, some days I'm the guy who needs the Denny's menu.
The next task will be to adjust the shoes and parking brake cables and bleed the brakes. It seems like I've been saying that for months.
In addition to the brake system fun, I checked into the turn signal cancellation issue that I discovered. I pulled the steering wheel and checked the cancellation ring which is in good condition. So I activated the turn signal as if I were making a left turn and attempted to trigger the reset manually using a screwdriver. To my surprise, it didn't work...it's a NOS Koln column that will now need to be taken apart (Noooo!!!!) or swapped with my NOS SWF column.