a japaneese mvt is something scammers are "offering" unless we are talking about quartz. swiss mvt is very hard to find, very few reps have been made with swiss eta valjoux 7750, and if you find one, you still don't know who assembled the watch.
if you sk me, the a7750 is just fine for the money, then wear it out, and have a swiss eta installed by a forum modder, domi (dmuit) charges 300euro to swap the a7750 for a swiss, when he runs a campaign. IIRC