Conversation so far:
How do celluloid records have anything to do with Laswell?
Laswell became the de facto house producer for Celluloid until the sale of the label in the later 1980s.
Where were they located?
Within a few years of moving to New York, Laswell founded a recording studio.
Was there anyone else involved in the label with him?
with producer/engineer Martin Bisi (of later indie rock renown) and hooked up with Jean Karakos and his fledgling label Celluloid Records.

Question: Did any other artists record under that label, too?
Self-contained rewrite: Did any other artists record under Celluloid Records label, too besides Bill Laswell?