[SD ///M4]

Update:

I got the elbow from the dealer and it's the same as the other two in my picture. The long end plugged into the vent tube and the short end plugged right into the new battery. Finally got it back together today.

Not so much luck with replacing the positive battery terminal cover which is what I was waiting for before I buttoned everything up. The two access flaps on my cover were broken off. Apparently this is not available separately but is part of an assembly which includes the cable that disconnects in the case of an accident and another cable that goes to the power distribution box. My dealer quoted $197, so that's not going to happen. I just put the two flaps back in place and taped them down with some red electrical tape.

Here's a picture of the cover that Ron Stygar posted here in the past. The cable that disconnects in case of an accident is partially visible on the left side. The other cable goes to the right to the power distribution box: