I don't think you'll be thrilled with this:
It burned down on 11/23/1986, according to this article,
http://articles.latimes.com/1987-02-04/news/mn-536_1_altaden... . Then there were scandalous charges against the owners and son of the facility in 1987-1995, who also owned Lamb Funeral Home, which can be found by an internet search. However, in the 1940s-50s-60s-70s, the facility was highly respected, apparently.
I just found that a relatives ashes were shipped from a funeral home to Forest Lawn, Glendale, CA, several months after his death in a neighboring state, and then they turned the ashes over to Pasadena Crematorium. In the meantime, my grandmother, who had made the arrangements for him and lived in LA with my parents apparently was not contacted, and F.L states that they had no contact information. I do know that the original funeral home did have that contact info (and attorney contact info) and it is also on the death certificate.
Basically, I'd like to know what would have happened to the records for Pasadena Crematorium, but assume that someone at F.L. thought the ashes were unclaimed, and "disposed" of them to Pasadena Crematorium in 1958.