Did a bit of backtracking in order to get a better seal on the doors. I cut back the outside flange after reestablishing the 1/4" gap. I think having established that gap before fitting the door locks contributed to the gaps getting tighter. In any case, I was able to cut the gap back but had to backfill in a few places with epoxy to get an appropriately sized mounting flange. I'll see the results tomorrow but everything appears to have worked out well. Today's work was on the right door. I'll tackle the same task on the left door tomorrow.