As mentioned above. A “Swap Job” is a Genenstein (dumb word) at the end of the day.
Because Rolex doesn’t publish/track numbers. If you end up with a complete/correct 1680, 16610, etc., with all genuine parts it IS GENUINE. No need for the stein. If the 1575 came out of a DateJust and now powers a Submariner it’s all the same. Rolex never differentiated why should we.
If a 160x becomes a 1016, then it’s a swap job. Again assuming all genuine parts but some mismatched component like the mid case.
And to recap, a Frankenstein is a mix of genuine and aftermarket/replica parts.
Thats how I see it. However, Rolex purists will probably refer to a Frankenstein as anything different from the way it left the Rolex factory. Don’t get me started on Rolex purest. 😉