FWIW, A/Z had the fitting and it'* steel, Dorman # is 500-048.

Coincidentally, that is where I got he plastic elbow, which was the exact same one that was in there, and had failed. It was on a display behind the counter, and I imagine it is requested often, when you consider how many 3800'* are out there. I remember feeling fortunate to find the exact replacement, I should have asked if they had the steel one.

Is the steel one dimensionally the same as the plastic one?

Steel is all they had, and it had been put in the wrong place---I'd all but given up in the search when this gal that worked there found them.

Mine wasn't an ell, just a straight barbed nipple, but yes, absolutely identical. It uses an O-ring to seal against machined boss. Straight threads, but with all the grief I've had in the past in using steel in aluminum. It got a good dose of teflon goop, more to keep it from seizing, than sealing.