What is the difference of the BMA's & AKM's on a D6Mxl ? Origin ? Weight ? Mechanical difference ?
Not sure you have your S/N prefixes correct. AKM is a French-built D6M with a 3126B engine. BMA is the prefix of a 3126B engine model that is used in a list of machines as long as your arm - including the AKM-prefix D6M.
Is there an USA made 6M, what is the S.N.?
Not as far as I can see. D6M Manufacturing location options appear to be France, Brazil, or Japan. For a machine sold into the US it would be most likely built in either Japan or France. Brazil probably builds the machines for the non-emissions regulated (LRC) markets.
New d7s and d8s are made in Brazil for US markets
Does the AKM's D6N use DEF ? I think it's a 03 mdl.
The engine is only rated EPA Tier II for emissions, so no.