My guess is that this uniform was worn during the Vietnam War but it had a different SSI sewn on the right shoulder.   This sailor was probably active duty during the war with one of the IUWGs in South Vietnam and after the war joined one of the stateside MIUW Reserve Units.  This sailor simply removed his active duty patch and replaced it with their generic reserve unit patch.  You didn't see this triangular patch being worn until maybe the late 1970s and early 1980s.  It is their earliest design as it changed background colors and wording (see photo).  You see it worn on BDUs and on the various desert pattern camouflage uniforms.  Their history is convoluted and hard to follow as they kept changing designations and I think the US Coast Guard has taken over some of their functions regarding the force protection of harbors.      

. Back in the day 2014 on Amazon.   A couple of posts above I mentioned that I had taken a screen grab of prices for my book on Amazon,  I thought the highest price I had seen was $1,184, now having found the screen grab again it was actually $1,899.33. which was really weird seeing all the books at lower prices mentioned above this price.      Norman D. Landing, Forum Normandy Correspondent, 17 April  2O26.   ..

Thanks for your help John

You have a picture of the device on the canopy without the gunner in the way?

The best thing is to get it to someone who will take care of it whether an institution or an individual.   

A possible place to donate the items would be to the National Museum of the Pacific War in Fredericksburg, TX. 

If patch is a period one with shirt then worn in Vietnam, then perhaps a member of  Inshore Undersea Warfare Group One.   http://www.iuwg1.stabledoorveterans.com/history.htm

The very first batch of 1219C2s provided to the USMC by anyone was in December 1942 and made by Union Cutlery (Kabar).  These knives had screw-on pommels.  This was per design specs.   After the first batch was delivered to the USMC, it was quickly discovered that the screw-on pommels would loosen up, leading to knife failure. , So the Marines implemented the first "change order".  That change was to weld the pommels tight after assembly.     The first batch of Camillus USN-MK2s (shipped in January 1943/received in February 1943) were 1219C2s stamped USN MK2 rather than USMC.  That is the only difference between a 1219C2 and a USN-MK2.  It's also why I call all USN-MK2s a 1219C2 when typing quickly.   This first Camillus batch was made per the original specs, which included having screw-on pommels.  This batch shipped before the first change order was promulgated/issued.  All subsequent Camillus USN-MK2s  were produced in accordance with whatever specs were in effect at the time of production, as did Union, Pal and Robeson.   The second batch of Union/Kabar 1219C2s had screw-on pommels that were then welded to prevent accidental unscrewing/disassembly.  These can be identified by looking at the pommel face - they have what I call a "round weld scar".   None of the 1219C2s and USN-MK2s made by Robeson or PAL were made with screw-on pommels, to my knowledge.   The second change order basically answered the production question - If we are going to weld the pommel tight, why are we wasting time threading the pommels and tangs?   If we don't thread the pommels and tangs we can make XXX???? more knives per day.   This lead to the change order removing the requirement for the pommels to be threaded on in the first place.  These knives have a "square" or "rectangular" weld scar.   The next two changes were pretty close together - (1) movement of the stamp from the ricasso to the guard in a mistaken belief that the stamp was causing the blades to break at the tang/blade junction.  and (2) reduction in pommel thickness from 3/8" to 1/4".  This change was to reduce the amount of steel being used in the pommels by 33%, not much per knife but literally tons of steel saved over the course of the remainder of the war production.

Here is a controversial Oval attributed to the 503rd. No need to rehash the argument unless it can lead to a definitive answer. Forum members have expressed their opinion as well as several books on the subject of ovals, favoring the 503rd or refuting as such.    

Mark any markings on the otherside? Orientation and placement of SF DOL crest will tell a lot. Although that is the presentation side...It could be a legit sterile early iron guard but the Pak copies also looked similar. But the blade shape does look good. Blade length?