Buy one, overnight just the frank between two containers of blue ice to John Fox, and you will have a definitive answer the next day!
Assuming you were not lied to (above the claim the franks were made especially for them,) the usual suspects are:
1. Boar's Head
2. Nathan's
3. Sabrett
All three have a New York address on retail packages, only Sabrett is physically manufactured somewhere in the State of New York. If the franks are not laced with garlic, chances are it is a Boar's Head. I can't see smaller NY brands such as Sahlen's, Hofmann's, Hartmann's, Stahl-Meyer, Karl Ehmer, Schaller and Weber, Golden D, etc. being available at a price attractive to a hot dog vendor in your area. Hebrew National is no longer made in NY and has a Omaha, Nebraska ConAgra office address on the package.
Even if the vendor won't tell you the make of the hot dog, you should be assured that it is not a brand that retails for $1 to $1.50 a pound. For some on this board, it is a sport to reverse engineer what a hot dog vendor is using. The economics of the business along with food safety issues dictates that just about everybody BUYS their hot dogs from a USDA-inspected plant.
<message edited by David_NYC on Fri, 09/17/10 9:45 AM>