How rare is a '72 Blazer with a factory 4 speed?

[Roberty]

I looked at a '72 Blazer today (2wd) with a friend of mine that was bought new by a local guy. He's wheelchair bound now (The guy who ownes the Blazer) and can't drive it anymore and is going to sell it. I looked in it and noticed it was a factory AC, V8 truck and was expecting an automatic transmission but low-and-behold it had a granny geared 4 speed trans in it. I looked at the options sticker on the glove box door and it was listed as having the 4 speed trans. The owner stated that he had special ordered the Blazer as soon as he got home from serving in Vietnam. He stated that he had driven it from Alasaka, all over Canada, to Central America and just about any other place that you could mention in it's early years. Anyway my question is this : How rare is a Blazer optioned like this one is? The truck is a one owner '72 2wd with factory posi rearend, 350 V8, 4 speed tranny, AC, front sway bar, etc... but it's not a CST. He claims it's one of only 5 produced like this - I have no idea where he came up with this figure. He's asking a very reasonable price and I told my friend that if he doesn't buy it I will, but he has first shot at it since he used to work with the guy and he found it. Does one out of 5 produced sound likely?
Sorry for the long post.
Robert