TubeNet

http://www.ebay.com/itm/Euphonium-Wall- ... 500wt_1413" target="_blank

I would bet that the image is 'flipped'.

Looks like a custom job to me. If you look at the near side of the bell, you can see a line (level with the mouthpiece receiver) where the leadpipe probably attached to the bell originally. The entire instrument looks like a standard "right hand" model *except* for the leadpipe (which includes the main tuning slide, part of which is visible on the far side of the bell, between the bell & valve cluster). I'd guess this was reworked for a player with some sort of damage (or other problem) to his/her right hand.