Not sure on the beavertail but The Daly Gun in 20 bore did have shorter tubes. Looking forward to see the images. I did stumbled upon an article in Typo Graphic from 1949 that noted that August Lindner of Suhl made The Daly Gun and his two sons were killed in WWI and his father died for old age. Purported that the tubes were sourced from Belgium & the mechanism from England.

Cheers,

Raimey
rse