Entering this Mary Poppins: And 19 other children's Favourites release I found the artist given on the CA to be The Main Street Band and Orchestra (not "The Great American Main Street Band").
See CA inside booklet. (large)
Listening to the CD revealed a extremely wide array of musical styles. And ... well one thing led to another and now I suspect that The Main Street Band and Orchestra may be a publisher's conglomerate "artist of convenience".
If I'm correct then (so far):
Track 6 The Conga has the same name and publishing company (Rainbow Media Pub. Ltd.) as a 2007 track on release titled " The Children's Party Album", which gives the performers as "The Pop Party Allstars".
Track 17 Arabian Dance (from The Nutcracker) is the same recording as The Nutcracker: Arabian Dance by the Adelaide Symphony Orchestra with conductor Jose Serebrier.
Sony TrackID on my phone tells me another one is credited to something like "Capitol theatre cast" on a Snow White release by a related publisher. (I don't have these details in front of me so may not be right details.)
It's all very puzzling.
Is attribution to the correct artist something that is often signed away in recording contracts?