Don't suppose anyone knows of schools versions of musicals like My Fair Lady with CDs. Any recommendations would be welcome though. Age group is primary (7-11).

You may struggle to do musicals in a primary school which were originally written for an adult cast as many songs will be in the wrong key for children's voices. There are companies that specialise in producing children's musicals. Try an internet search for musicline for starters. There is a lot of material published for Christmas and Easter. Try the catalogues of Kevin Mayhew, A C Black and Faber music.
A local school near me recently did Oliver and other musicals for children that spring to mind are Annie and Bugsey Malone. The adult roles in Annie may be a problem. Bugsey was written for children but you will have splurge guns to contend with.

Try looking at the Broadway Jr. Collection and the Roger's and Hammerstein's Getting To Know Collection. Both have cut versions of popular musicals with keys transposed to be conducive to young/changing voices. They come with CD accompaniment, a director's guide, a video to help teach choreography, and probably some more stuff.

That brought a smile to my face.

You could combine other musicals as well. How about Oliver and the Phantom of the Opera, or Cats and Guys and Dolls?

At the school I've been working at recently, Year 6 did a production of Romeo and Juliet, which the children re-wrote themselves (having studied it earlier in the year) and combined it with songs from Grease.

Although I personally think some of the lyrics in the Grease songs were a bit adult, it seemed to work quite well and most of them seemed to thoroughly enjoy it.

So getting the children involved in creating a play and then incorporating existing songs can work well.

Last Christmas the primary school at which I used to work put on an old time music hall. The two top years took part and it was a lot of fun. We learnt lots of songs of the period as part of the project on the Victorians and then worked them into a music hall show along with dancers, a magician, jugglers, a ventrilloquist act and a chairman introducing everything. Many thought that it was their best production.

At my school, some people did a musical that a teacher made-up. You could make a easy play.

My primary school did a similar thing, many years ago.... It worked very well!

How about Ocean World by Peter Rose and Anne Conlon? When I was in primary we performed lots of their shows - all very ecological, Ocean world is about a whale and her calf and the preservation of the ocean - it's beautiful and very sad. I've since taught it to other primary age kids and they love it. It's published by Josef Weinberger and comes with a CD. Only downside I can think of is that the CD is with voices so can't really be used as an accompaniment, and the piano score is fairly difficult (not overly, but certainly not for beginners!)