Welcome to C-C.com! This is a great site, lots of information and very helpful, friendly people here. If you're planning on hanging around, start a thread on the Newbie page and tell us a little about yourself. If you buy the car, make sure to upload some photos.
Using the VIN decoder (found under "Tools" on the C-C.com home page), your VIN decodes as:
1972 Barracuda Special (BS), 2 door hardtop (23), 318 2 bbl (G), built in Hamtramck, Michigan (B), sequence #371438.
I don't know much about production numbers, but I would imagine a 318 / 3 speed combo would be pretty rare. By 1972, three speed manuals were pretty much gone (probably some /6 strippers) - most standard V8's would have had autos.
On a side note - 100 posts!!
Greg