i have read every post on this board over the past few days and havny seen this brand mentioned. its a german company with roots to basson making but made fantastic clarinets. i am lucky enough to own one and can attest its near the top as the finest i ever played. no need for a pic as it looks like every non discript wood clarinet ever made . no frills or unique keys etc. its simply amazing to play. aas good as any r13 i have played and better than the one i own very little info on the net but there is a wiki
https://de.wikipedia.org/wiki/Püstophon. i would mine on a clearance table at a pawn shop for 10$