I wonder if that’s why there are two different “spellings” on there headstamps? One being all caps (GECO) and the other just initial caps (Geco).There's two Geco's (three if you count the one that sells insurance): Geco could be Dynamit Nobel A/G, Troisdorf, Germany; or it could be Gustav Genschow & Company, Durlach, Germany. From what I've seen, they're the same quality. Source for this is the IAA's headstamp codes page, linked above.