Thomas Arne - Alfred: The overture in the vocal score

[KarlAksel]

I notice the vocal score has the piano reduction of not only the original overture, but also a second (incomplete) overture which I do not recognize and which appears to have been included by mistake before the proper overture. The mistake is that of the 18th century publisher, not the uploader, just to be precise. But does anyone have any information about that partial overture?