The rifle from your link seems to be done as liners in the old shot tubes, judgeing from the picture of the muzzel end picture! I would be real worried about how this rifle was regulated, or if it was at all! The removal of the express sight, and the addition of an adjustable ghost ring sight indicates an attempt to fix a sighting/regulation problem to me! This rifle looks well done, but silk, and lace aren't exactly what regulates a double rifle ! The rifle is chambered for an excelant cartridge, and has selective ejectors, and if it shoots properly, is worth the $3900 USD, if it doesn't shoot properly, then it is simply a start to build a double rifle, and not worth the heavy price for gun parts!