Please ID these US Army Unit Crest.

[Manchu Warrior]

I actually have the U.S. Army Heraldic Crests Book but unfortunately I buried in a box somewhere. I not sure how I should feel about the fact that I cannot locate a huge thick book somewhere within my collection? With that said I purchased a pile of crest today at the flea market and I cannot ID these three. One of them actually has the unit motto on it, First Rocketeers, and for what ever reason I still can't find it. I appreciate any information. 

 

[tredhed2]

First Rocketeers is 763rd FA Bn c. 1956

[tredhed2]

Bottom left is 503rd S & S Bn (3rd Armd QM Bn)

Far right is 15th F Bn

 

[collectsmedals]

The one on the right still attached to the backing is the 15th Field Artillery regiment (15TH FA) This design was approved September 14, 1922. The regiment, which was organized in 1917 was assigned to the 2d Division in World War 1. The five wavy bars on the shield represent the French rivers: Aisne, Marne, Meuse, Moselle and Rhine which the regiment crossed. The canton is from the coat of arms of the 4th Field Artillery and represents formation of the regiment by transfer of men from that unit.

Source: U.S. Army Heraldic Crests by Barry Jason Stein

[collectsmedals]

I see the identification was already there, I think I was still typing when tredhed2 posted.

[Manchu Warrior]

Haven't been on for awhile and I appreciate the information. Thanks!