Snap-on Proto type nut driver

[Woodshop Woody]

I have a standard nine piece nut driver set with case, model number NDI 90 I believe it is a prototype I bought it off the snap on truck in Wisconsin 20 years ago and I Can't find any information on it I was told they only made a few sets and they were trying them out to see how people like me like them does anyone know how many they produced or what the set might be worth?

 

[MattVette89]

Here's a set that sold on eBay for $28 if that helps with value:

http://m.ebay.com/itm/161593784957?nav=VI

 

[3baygarage]

Definitely not a prototype. I have some of those shafts I found locally. Who knows how many they made though. A set that isn't seen as often as one piece nut drivers.

 

[Mopar-Scooby-Doo]

Those look just like an xcelite set I have. Minus the snappy handle of course. I'll try to post a pic latter.