Use the .f3d model in Fusion 360 and adjust parameters as needed to fit your watch.
Parameters:
Number of Lugs
Lug Width
Lug Inside Diameter
Lug Outside Diameter
Recommended to include some offset on measured dimensions for a proper fit (vary per printer) However outside diameter can extend a slight bit past measured outside diameter to ensure full engagement.
The author marked this model as their own original creation.