My, that is an old AP600 - I was expecting the Takahashi-copy AP600E, but this is the older version. Parts will be nigh on impossible, but if you ask George at AP, he MAY be able to find something. he found me some items discontinued in 1990, so you just never know!!!
Here is a link to a similar 600:
https://www.cloudynights.com/topic/5...ts-a-new-life/