NEED HELP! With a D.S.O. code question

Hi new to the site I posted this in the discussions forum, probley wrong one. I bought a 1970 mach 1 for a 1,000.oo dollars witch been sitting. in a barn under lock and key.The vehicle is all there except for both door panel, head liner jacked up along with the windshield. The guy I bought it from need a new washer and dryer and needed money he want 2500 half of what he paid 14yrs ago from his uncle who had a gold one also maybe thats why the door panel missing.Any how some paper work in the glove box stated the D.S.O. is 723K San Jose (Special Order Unit 3K).

What does the Special Order Unit 3K means?
This car is straight solid vehicle paint looks re-done super dark green.I found the color codes and all its suppose to be Ivory green but looks darker then that. The engine looks to have a 4bl and add on's pretty clean turns over want start, thinking its just a fuel issue. Thanks for any help.

Shawn

P.S. Not a computer guy I'll try to get some pictures up with my wife or daughter help. One of my Buds offer me 5,500.oo for it not for sale.