The drain line in the wall was not centered on the tailpiece. It was not off enough to use one of the offset pipes with two opposing 45's, at least in the depth that I had. So, I got the outlet of the trap with its accompanying 90 degree to line up with the height of the drain line coming out of the wall, and was able to make the connection with a 45 on that pipe.
One other question: At the same time, I installed a
RedyTemp hot water recirculation system. It starts and runs quietly as you'd expect from this type of pump, but does a 1-2 second sort of rattle when it turns off. I'm going to query the manufacturer, but do you have any thoughts? BTW, it took all of about 3-minutes to install and seems to work fine. It has an adjustment on the front to set the turn-off point that I may tweak over the next few days. Now, instead of running the shower for over a minute to get hot water in the morning, it takes less than 5-seconds. Getting hot water at the sink to wash your hands took even longer, now its warm almost immediately, and hot shortly after. Not much warm water in the cold line, either (no separate return line in this retrofit).