It is? The link goes to Google.nl but the text should be in english??
There are some more numbers missing in the list, maybe companies who quitted, or they didn't meet the NSF standards anymore? The list above is from 1968. Maybe another company got that number afterwards?
The logo was blue gray and white, and the number was right under the seal. Like this one:
I'm still trying to find anything online about the seal and that number, and I hope the investigator got my email.
There was/ is an NSF Eastern and Western Region, Eastern Region was/ is in PA, according to the two adresses below, of which I hope they show up in English and not in Dutch