Here is a place to start.
http://www.nostalgiaair.org/PagesByModel/986/M0013986.pdf
This D-10 record changer was used on several of Philco's models in the 40's and early 50's acording to their literature.
Doug
Thank you so much for your help. Unfortunately, that is not the record player in my stereo. Mine has two different sized arms and looks a little different. any other ideas would be greatly appreciated! Again, thanks so much for such a quick reply!
Andrea,
According to different references I have you could have either of these record changers.