I found two puzzles with the same cut! They are Tactic 500-piece puzzles, Waterhouse and Palm Beach. Makes sense that smaller manufacturers would use the same dies for all puzzles with the same piece count, whereas large manufacturers have different dies and even the same images can be differently cut. As I suspected, the mashup results were hardly spectacular, but I’ll continue to keep my eyes open for possible combinations.
That was fun! Hope to find some more striking combinations next time.