Trap for very narrow "hand rinse basin"
I'm trying to do the drain for a "Porcher Elfe" no-overflow sink. This is a very narrow sink (for our very narrow half bath) - the drain hole center is 3.5" away from the wall. I first removed the chromed brass wall piece that stuck out quite a way - thanks to searching and reading previous posts, I was able to identify and remove the solder bushing in my CI stack, by hacksawing out a section.
My thought was to use a bottle trap, as that seems to be what's in all the pictures I could find of these european style hand-rinse sinks. Unfortunately, the sink drain is 1/2" offset from the wall opening. I'd love to avoid moving the sink if possible (wallpaper cut/installed around the existing location), and the local plumbing supply sold me a brass 1-1/2" to 1-1/4" trap adapter with rubber washer and slip nut - he said it would likely maintain the seal while allowing the 1/2" offset to the bottle trap. After screwing it into the wall, I'm not sure there will be room - haven't bought the bottle trap yet.
Is this a viable route? Other thought I had was trying to somehow link up a "double offset" to the drain, to allow a p-trap to come back in front of the DWV. But this or other p-trap options seem like they might be pretty ugly in this exposed location compared to a bottle trap. Also, if I do screw in a brass adapter into the cast iron, do I need something on the threads?
I'll try to include some pictures of the situation. I appreciate advice!!
btw, I plan to replace the left shut-off valve with the right angle style that is on the right.
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