Originally Posted by
malcala622
Suntour FW, Dura Ace FW and BSA lockring goes into bmx hub with no issues.
Dura Ace FW doesn't go into 105 hub.
I like your "NOS" theory. I bet the threads of the hub need to be worn in a smidgen. I also bet the threads on the SunTour freewheel were machined to a slightly looser tolerance than the Dura-Ace freewheel.
In my years working in the bike business I never saw a French-threaded Dura-Ace freewheel or French-threaded 105 hubs. They might have been made but I would lay long odds against it. Both were made after the time the French started adopting English threading for many of their components.
If these were my parts I would not hesitate to build hub into a wheel and then thread the freewheel on. If it stops, double check that it's going on straight then crank on it with a chain whip.