Maybe it was a gift. Having a gift engraved is nothing unusual, and maybe the person who gave it to him knew nothing about guns.
In the early 1970's I once toured the Mossberg factory and was proudly shown a highly engraved and gold inlayed Mossberg 810 rifle which had been made for President Nixon to present to Premier Leonid Brezhnev of Russia. The engraving was gaudy and underneath it was a Mossberg rifle. Clearly the person who ordered it had no concept of what constituted a desirable firearm.
Maybe Mr. Carpenter lived in Philadelphia at the time and Sedgley was more convenient.
He doesn't look like the kind of man who would know the difference between a Sedgley and a Griffin & Howe, or for that matter who was capable of firing a rifle in the prone position.
