Go here for German weaponry:
http://www.geocities.com/Augusta/8172/panzerfaust.htm
The number of the MG, is when the MG came into service. So, the MG34, went into service in 1934...same as the MG42, it went into service in 1942. So, that's why you don't see a MG35, MG36...it's not a production number, or serial number, it's the year it went into service.
This was normal military practice, and was done by most countries, when issuing new equipment. Stielhandgranate24...issued in 1924, 8.8cm Flak36, issued in 1936, etc.
MG42
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34th SS-Freiwilligen-Grenadier-Division Landstorm Nederland
"Meine Ehre heißt Treue"