I like the question and want to add a funfact. The word "Frankenstein" suggests to me rather a watch mixed from all possible parts - without the goal to improve the quality of a replica. So rather to produce something new. Frankenstein is put together from everything that existed. My 1st association of a "Frankenstein" was therefore a watch mixed from different models. Example: a 16610 Submariner case with GMT function and pointed crown guard like this:
How do you call this mix? 😉