Looking closer at this, there are a couple of issues.
I don't think it should be name "El." in either case. We shouldn't abbreviate names. It could be "IRT Third Avenue Line" like wikipedia suggests or the official name from MTA, or IRT at that time.
But more importantly, I don't think this feature should be mapped AT ALL. From what I see this line was last in service until 1973 and the demolition completed in 1977. There's absolutely nothing left of these segments. OSM is a map of the world NOW, not how it was almost 50 years ago. This should go into OHM.
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            Published using OSMCha: https://osmcha.org/changesets/146085221
            