Re: Superseded military (MIL) specs
I dealt with this situation during Contract Review with my own company simply by calling a customer's attention to the fact there was a more recent revision (or that the Military Spec system had been abandoned and turned over to commercial Standards.) With that, we WROTE
"We no longer have a copy of the obsolete specification. If, for some reason,you want us to build to that specification, could you please forward a copy of it so we may comply?"
Sometimes we were aware of differences in revision levels or that the commercial Standard was identical to the military version. In those cases, we pointed out the difference and asked IN WRITING for the customer's requirement.
The delays arose when the purchasing functionary was incapable of reading or interpreting specifications and was incapable of framing the question accurately to his engineering department. Some customers were so bureaucratically snarled, it took weeks of negotiation before we could get direct contact with an engineer (I guess those companies are afraid a suppler will suborn an engineer?), who usually said, "Oh spit! How did that get by us? Yeah, sure. We'll update the drawing and forward it to you. No problem."
My advice:
Remove fear! Do not be afraid to raise the question if it comes to your attention. There are valid reasons customers want the original specification adhered to. It pays to know what they are. If they do want the most recent one, you look like a hero for bringing it to their attention!