Church Screening & Demolished Long Beach Ballroom Location Question

We went to the screening at the downtown Los Angeles church last night and had a fun time. I was surprised by how many interiors were filmed in the real church because I knew that some of the main interiors were filmed in a now demolished ballroom in Long Beach. The main congregation area has been remodeled extensively. It served as the staging area for the scientists in the film. Other real church interior locations were the lobby and stairwell and the back offices where labs were set up (mostly modified beyond recognition). The exterior stairwell and walkways have also been modified since the 80's with a few of the older doorways and windows now cemented up. Horror's Hallowed Grounds had a great little Then and Now video dissecting all of it which I'm sure it'll be online soon if it's not already. I get the impression that this screening may become an annual thing if there is interest. I'd be on the look out for one next year. But you could also always go see a play at the space put on by the East West Players.

I tried doing some research about abandoned ballrooms in Long Beach in the 80's. Cinderella Ballroom? Fender Ballroom? Does anyone have a clue where it was? I'd love to find a pic of it in it's glory days. Those hallways are very particular.