Found a refinished Rival No. 3 - no engraving and Twist barrels. Like the No. 8 linked above, pre-1893 proof marks (the ELG in an oval is not crowned), and no maker's mark.

[Linked Image from photos.smugmug.com]

Interesting floor plate

[Linked Image from photos.smugmug.com]

Let us know if you come up with a Van Camp catalog.