Very nice jacket, and a very generous friend as well.

On references you might try this one.  It was published quite a while back but would likely have some useful information for you on Naval arms.  

I did a test fit of the trigger group parts last night. I was simply unable to compress the plunger spring enough to get the hammer pin inserted correctly. It looks so easy in the online videos. Gotta do some more thinking on this one 🤔.  mikie

Hello Everyone,  I just received this today. It belonged to the father of a new friend. His father was a Grumman field rep that according to him sailed on these ships for Grumman to give the navy technical assistance with certain aircraft.  The Tonkin Gulf patch has to be my favorite. I hope everyone enjoys the photos.

Here is a Hand special MOH Society special edition .buckle      

For clarification, my post #53 was directed to sigsaye.  Thank you also DD937 !  On a related matter, was the group name Fireman replaced by Engineering, or just used for clarification to the students perhaps?  Were the titles Seaman / Deck also used that way?  Thanks again!

Allow me to join in:     WN60 is one my fav spots to visit, along with the Batterie de Longues-sur-Mer.   Omaha Beach at sea level, 2020:     Hard to believe what happened here on June 6th 1944, such a nice and quiet beach it is now...   My jeep on Omaha Beach, directly below the 5th Engineer Special Brigade-memorial in 2004:       Most of you will have heard the phrase 'Bocage', meaning the small tracks with high hedgerows on both sides that acted as field boundaries in the Normandy hinterland. Below is a pic I made the last time I visited Normandy, in 2020. The enemy could be waiting in ambush literally everywhere, and there weren't even the densest bocages I came across.          

. late WWII photo, gathering souvenirs , young guy in the middle has a bugle next to his German weapon.  The guy far right has an unusual shaped pipe.      regards lewis.   ...

OK, I finally read your post more thoughtfully!  I understand now that the Apprenticeship Training Units used the Seaman, Airman and Fireman distinguishing marks with the group rates to sort the students into three schools ( I think).  These must not be too common; I have not seen this combination before today (not that I'm an authority).  Thank you for the clarification.  Do any of you out there have or have seen this combination?