Later today I will post pictures of my Trap Grade. I noticed the engravings on yours appear a little different than those I have seen. This does not mean much as there are indeed differences between each gun. More importantly though, your right side plate has more or less the same scene as your Left plate...on the Trap Grades I have seen, the right plate has a SINGLE shooter, shooting at a flying bird...not the group of shooters shooting a clay bird...
To my poor eyes...it also appears that the breech balls on your gun are somewhat different in style of engraving than those I have seen. This is hard to rationally discuss going by pictures alone...and I am sure the true experts will express their opinions...and I personally look forward to that. These are just my amateur views...I will yield to those who are more knowledgeable than I on such matters.