The 7753 would be an easier movement to replicate, especially as something else so similar (7750) has already been done, and a lot of the base parts are the same!!
Trouble is, as with many things in life, once a bodged solution is produced that enough people are prepared to live with then there is no incentive to improve on it. The transfer gears exist, so they are going to get used - even if someone has since taken the time to refine them a bit (as per the latest Navitimers!)
It's the El Primero I want to see repped though as it would open the door to a huge seam of accurate reps of desirable watches...
TAG Monza/Calbre 36, vintage Daytonas, PO Chrono etc. etc. etc.....