While I don't know, specifically, what you're talking about, the last 2 posts interest me.
1. Integration Authority. If you're talking about MoD as a whole, I thought we had an IA, headed by a 2 Star. Whether or not they've worked out what integration is yet (having only been funded to do this in 2001) is another matter. Meanwhile, those who did it for fun carried on regardless....
If you're talking about AWACS itself, and assuming there is a Aircraft Co-Ordinating Design Authority (as mandated), then he will be your IA. The same company would usually be responsible for e.g. the whole aircraft safety case. Even if the appointment has been made by MoD, they usually forget one minor thing. You also need a funded contract. (This is the failure at the root of Nimrod XV230, leading to Haddon-Cave. H-C criticised the Safety Case, but failed to point out that no contract had existed for many years).
2. STANAGS - There is an "Order of Preference or Hierarchy for the Selection of Standards for MoD Acquisition"
There are 9 (nine) levels. STANAGS come 5th, behind (e.g.) European (including British Standards), International, National (e.g. BRs not implementing Euro standards), Commercial standards recognised by industry.... then STANAGS...... then MoD Defence Standards (except those mandated by Secy of State, like 00-970, which are obviously called up anyway), MoD Departmental standards and specifications, other Nations' standards (Mil Specs etc) and finally Recognised Company Standards (e.g. Panavia, Airbus).
There are a number of problems with this (apart from the sheer number of standards to choose from), primarily;
a. The STANAG committees take FOREVER. If a decent STANAG doesn't exist, you simply cannot afford to wait. You usually find a better alternative among the others anyway. You may hit problems with interoperability between NATO countires, but (bizarrely) that is not Government policy anyway (and even more bizarrely, nor is interoperability between UK forces). You often find yourself calling up a STANAG, then falling foul of scrutineers who won't approve funding because it can't be reconciled with the endorsed requirement .
b. MoD staffs have, for approaching 20 years, been taught that none of the above is mandated or even necessary, and you can just let a contact and tell the company to do what they want. This particularly applies to the mandated Def Stans, like 00-970 and the 05-series, which are routinely waived. In fact, there are numerous formal rulings governing procurement that state this. As ever, this means your typical project manager doesn't know if he's full-bored or countersunk, with all and sundry being permitted to overrule him.
I think you may find a partial answer to your problem in the latter.