Early WWII USN Lap Belt pics or diagrams

[Kayjay]

Good day!  In the middle of Trumpeter's 1/32 Late F4F-3 build.  I am scratch building lap belts, forgoing the harness belts as they came later and would like the lap belt look, and am having a devil of a time finding any pics or diagrams.  The closest I have found is from another modeling site and I put the pic here (it's not theirs and is out there in the public domain).  This is a great pic, but I cannot figure out the belt latching mechanism.  Any help?  

 

 

Sincerely,

 

Another Over-Anal Modeller But Non-Rivet Counter

 

 

[Kayjay]

Help me finish the office...all OOB and on to scratch building.  Insight and critique welcome.  My hide is thick like my head.  Thanks