If it is of any interest,
I only own four Borchardt magazines, one for the gun and three for the carry case.
My numbers and size are as follows;
478 approx 2.5mm
496 approx 2.5mm
680 approx 2.5mm
3015 approx 4.0mm
I might add that I cannot see how a 2.5mm die could produce such a larger number as 3015 for not only are the numbers taller they are also correspondingly wider and thus produce a much larger size number group overall. This is evident in the photos posted above.
Sadly I do not own a matching magazine for the gun which is #315.
Regards
Murray