It was the lack of centre fire rook rifle ammunition being produced and the .22rf. that sounded then death knell. Main options were to re-bore to .410 or re-tube and convert to .22rf. or .22 Hornet. All those options can be found. The valuable ones now are those that are original.

Most of the rook rifle models had full length octagonal barrels and when converted to .410 had the main part of the barrel taken down to the round leaving about 8 inches of octagonal area at the breech to balance them better for shotgun shooting. Lagopus.....