Many, many thanks to all those who responded to this thread. I am so glad that I have now been introduced to PDQ Bach and I now have the scores to My Bonnie Lass She Smelleth and The Queen to Me a Royal Pain Doth Give. When I get the time I'll chase up the other Rounds as suggested.
The score itself is marvellous. It mentions that articulation is important and recommends a small chorus. Has anyone ever heard it done by (say) a hundred voices - I hope that we might give it a whirl? The score excludes some of the lyrics given above but this omission is noted, presumably to encourage purchase of the record. One feature I did like is that the required vocal range for each part is clearly given up front - She Smellth in particular looks like a demanding part for many singers.
Again many thanks, John