I asked about this last night but now that I'm home I thought I'd post a scan of it. My first thought with a chip that has a number like this is maybe it's from a lodge, fraternal organization or union local. So far I haven't thought of an organization with the initials "NB" though. And then again "1948" does seem like a date from when this chip was made. Incidentally, some of these chips are faded on half of them. Anyone seen this happen to chips before?