Frank Poretta is sometimes listed as playing Steve on this recording. Poretta played Steve in the first three performances of the run, with Bob Shaver taking over for the final performance. Listening to the recording and doing comparisons with other recordings featuring Poretta and Shaver leaves no question that Shaver, not Poretta, is Steve on this recording.
The origin of this recording is uncertain. It has sometimes been identified as being from a radio brocast, but that seems extremely unlikely as no radio announcer is ever heard on the recording. In one version of the recording that circulates, we hear three-and-a-half minutes of applause at the end, followed by a brief time when we hear the audience talking among themselves as they leave after the applause has stopped. It seems extremely unlikely that it would have been heard this way if it had been broadcast on the radio. (Some versions of this recording have edited out most of the curtain call.)
It seems most likely that this was recorded off of or directly through the squawk box (stage monitor). It's possible that it was recorded through the theatre's sound system as contemporary accounts of the production state that the production was amplified, but this seems a bit unlikely as few sound-system recordings seem to exist from this early in time. Most recordings from this period that sometimes get identified as sound-system recordings were recorded with the squawk box as the source.
In 2015, a German label, Cantus Classics, released this recording commercially. As far as we can tell, the release was not authorized.