Thanks for the recommendation. I'll check into that option as well. One thing I did find in the Machinery's Handbook (25th edition) was this regarding designated UNS threads:
"Designated UNS Threads - UNS screw threads which have special combinations of diameter and pitch with tolerance to Unified formulation have the basic form designation set out first followed always by the limits of size" (Bold by me)
So, if I am reading this correctly, the designer should have stated the Major Diameter for his thread immediately after the specific thread callout.
Think I'll go back to them on this, too. Thanks.