Yes, "Billy" and "Dreamgirls" were produced by McCoy-Rigby, the resident production company of The La Mirada Theatre. Back in the day, there were quite a few different production companies that played at the theatre. The city of La Mirada owns the theatre, and they kicked out all of the companies when they brought in McCoy-Rigby to run it. Luckily, MTW was able to relocate to The Carpenter Center in Long Beach, and they have been there ever since.
When I did my first shows with them in La Mirada it was still called Whittier/La Mirada Civic Light Opera.
It's great that they doing a new musical such as "Elf."