1887 without gauge mark|Winchester Shotguns|Forum|Winchester Collector

I just acquired a very nice 1887 in very good shape.  The color case hardening is still visible, the 30″ barrel has darkened to a deep plum with the WP proof mark clearly visible, the action cycles perfectly and locks up tightly, and the engraving on the left side is crisp.  None of the screws are buggered, and the wood is what you’d expect but in good shape.  The only real detriment to this appears to be a polyurethane (or equivalent) finish over the wood.  It has a 4797 serial number indicating 1887 manufacture (if I’m reading the serial number tables correctly, that is).

However, I don’t see the 10 or 12 gauge marking on the barrel as I’ve seen on later 1887s.  All of the engraving is highly visible, and I did a very close inspection just to make sure the gauge engraving hadn’t somehow worn away.  The only information I found online says that 30″ barrels were 12 gauge (from gun-data.com, courtesy of Madis’ “The Winchester Book”).

My questions that I can’t find are can I depend on this info without the gauge mark, and when did Winchester started engraving the gauge on the barrel?

And yes, I’m planning on buying the appropriate BP shells or reloading appropriately.