If you really want to get it right you are stuck investing $4,000 + in an El Primero seconds at 9 franken or gen. The most fundamental issues are case and case back thickness (7750 requires a thicker case). I also don't know whether they solved the asymmetrical pusher issues on the 7750 version. My simple rule of thumb is that if a gen dial doesn't fit (due to either case dimensions or chrono sub-dials or date window not lining up) it will never fit the "no worries" category. I have a well-functioning Palp contemporary Daytona but it never gets wrist time for that reason. You can't cure case depth.