That is a pretty old Pioneer changer. According to your link, it is M-Bus, which is good news, because the Alpine changers are M-Bus. There is a chance the Peripheral interface designed for Alpine changers may work for your application.
What does the connector look like on the back of the changer? If it is an 8-pin DIN plug, chances are you might be able to use the peripheral HONIL unit.
Don't know for sure though, sorry.
'01 DEP EX, and I'm workin' on it! (slowly)