AH Upgrade?

[Big Friend Ten (BFT)]

I respectfully request help from the Parker guys who have have seen it all and done it all...

The Parker records list #66248 as a D2 or GH 12 gauge with Damascus barrels made in 1891. The gun today is an AH upgrade, or at least I think so. It has Acme Steel on the top rib with a strange style of type, a grade 6 on the watertable, beautiful engraving, and shoots like a dream!

This looks like an upgrade but by who? Could it have been done during the Remington era which might explain the funny lettering on the rib?

Here are are a few photos with many more in the album at this link:
http://www.parkerguns.org/forums/album.php?albumid=294