Indeed the differece in the keys is width alone...
and the one thing about this machine is it only measures the tip 1/8th of the key so it will not cut sidebar cuts... some keys it cannot duplicated...
M3, primus, or everest even cannot be duplicated.
there is a machine that duplicates blanks on 3 axes and can supposedly duplicate these blanks... I can get back with you on the name of this machins if noone elxe has it by the time i get to my room.