had it before but now with the SN, its 1550
W. Collath Söhne 6,5x52R (25-35) with "Tesco" engraved Gerard/Berlin 6x scope
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=519381468

and thats realy old: G. Teschner & Co Cal. 5 bore double gun SN 449 with grip safety

its proably made before 1880 when G. Teschner was dying because the name of the firm was than changed into "G. Teschner&Co., W-Collath"
the No. 5 chamber have a loose fit with 20 ga BP shotshells and they will split most times but its possible to fire this stuff.
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=518924105