Spent a whole afternoon tinkering on the fridge. Some good progress was made, but in the process the scope of the project became unavoidably expanded. Probably another 2-3 weekend days to completion. Satisfied with the work so far. Among the bottlenecks is the fact that the new ignitor and flame sensor do not fit the existing holes in the bracket... close, but not close enough. I tried to "trim" one by chucking it up in a hand drill and turning it against a file. Close, no cigar, not going to ruin a serviceable part trying to make it something it's not. Will try drilling the hole out 1 size larger, see if that works.
Got most of the tin back together, new fiberglass insulation in the flue, new ignitor board installed, and new heater element connected. Discovered the rust on the front was worse than thought... had to strip EVERY piece of front trim.... will have to be sanded, primered and painted... going to lose original factory label in the process too, it appears. Damn. Will try to save if possible, but not at risk of needing to re-do the paint again in 5 years.