The following article may be of some help. Jon A. Schmidt, P.E. describes how to estimate the loading (and hence the anticipated damage) to a structure from an external blast. The results of these calculations can help you quantify whether or not you have a vapor explosion hazard...
The answer to your question depends heavily upon how complex your drawings are (whether or not you have to check the interfaces between parts, tolerance requirements, interchangability requirements with standard or custom parts, etc., etc.); how extensive the changes to the design are; whether...
I had a similar problem getting various military and older aerospace standards. What worked for me was to apply for a commercial account at http://assist.daps.dla.mil/online/start/; this took a few days (over a weekend) to have established. Then I had to download the newest version of...