Germany and Holland, in particular, have used brass extensively in their M1-type helmets' fittings. I checked out my post-WW2 German examples: M60-Mod1A1, M62-Mod1A1 and M85-Mod1A1. The M60 was the only one to have brass loops. The rest are steel. My Dutch M53 has steel loops - but this doesn't mean brass was never used. However, moving to the rim number, the Dutch manufacturer Verblifa stamps are very similar to the one in question - except there's a 'V' in front of the 'B'. This may simply not be visible due to mis-stamping, paint or corrosion. Another point, perhaps rather subjective given the quality of the photos (I know it's really difficult to get good photos sometimes, so no criticism intended), is the form of the peak in profile that looks more Dutch than US to me.
This link may be useful:
.: World War Helmets - Casque Modèle 53 :.
It's also a good idea to remember that European M1-types were exported by the manufacturers to each other's countries! So one country may have bought batches from 3 or 4 neighbours. The above linked site gives useful info on this by country. Best Regards,
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