I have a Luftwaffe M40 by Quist in what I consider quite good condition (I don't believe it was worn much), and the only thing that I don't care for is the chinstrap. It's somewhat different from most of them I've seen, and reminds me of a buckle on a Luftschutz helmet an uncle brought back. The buckle portion appears to have been put on slightly "wrong" at some time, but I don't really want to bend it back the other way and take the risk of breaking or cracking it; the long portion is sort of "roughed up" on the right side where it has been run up and across the visor of the helmet.
The buckle itself is magnetic, so it isn't aluminum or some mystery metal. There is no real smell to the leather, so I don't think it is either new or recently aged.
Any thoughts on this one? In condition, it appears to be consistent with the rest of the helmet, but I have been wrong before.