Anyone know about these? : Markings on 3-inch rifle sight seats

If you haven’t noticed, I’ve taken some time during my visits to Gettysburg “getting to know” the 3-inch rifles pretty well.  My goal was to compile a list of markings and other features as I entice the stories from the guns.  One set of markings has me stumped.  Take a look at the hausse seat on the back of an Ordnance Rifle near the angle.

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Hausse Seat from #758

Here’s the seat from the front.

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Stampings from a different angle

The number “2” is clear.  The smaller stamp appears to read “3INCHGUN”.

The stamps appear on other guns at Gettysburg.  Number “4” is nearby.

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Hausse Seat with #4 stamp

I’m curious about the significance of the numbering.   I’d be shocked if the number was the serial number of the seat (what are the odds that 2 and 4 are nearly side by side at Gettysburg?).  Were the numbers perhaps an indicator of the gun’s assignment within the battery?  In other words indicating the 2nd and 4th guns in their respective batteries?

The screws attaching the seat appear to be post-war.  Perhaps added after the guns arrived at Gettysburg as part of routine maintenance.

Most other 3-inch rifles have flush screws, for obvious reasons.

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Hausse Seat from #533

Few others have the stampings on the seat.  Perhaps the stamps seen on #758 and others were part of a localized convention – maybe set at a specific armory or installation.  Since only a handful of guns have the seat stamps, the practice must not have been widespread.

If any readers have any additional information on the hausse seats or stampings, please do drop a comment here.