Thanks for the info - I had a VAM1202 lying as a spare for about a year and had not replaced it in my 15+ years old CD63, but got around to doing the swap today. The original CDM 12.1 laser unit had been replaced earlier with a VAM1202, and that one was flaky in reading the TOC, had long delays in playing tracks, and sometimes refused to play the track. I tried cleaning/replacing the flex cable, reflowing solder joints on the RF amp board, etc., but nothing seemed to work reliably, so I finally put in the new VAM1202.
... The CD 63SE would not play some CDs at times. ...
The issue was resolved with a small tweak.
The new unit did not require adjustment of the laser bias current - it worked straight away and is very quick in reading the TOC and plays fine (I haven't checked CD-RW yet, but I've never burned audio tracks to CD-RW, only CD-R).
My guess is that the old VAM1202 is also serviceable and can be made to work fine just by a slight tweak to the laser bias current, so I'm keeping it as a possible spare.
However, I noticed a slight difference in the CD presence detect sensor - the old VAM1202 pickup had two copper contacts that are normally open (i.e. don't make contact), while the new replacement appears to have contacts that are normally closed. Since it seems to be working fine, I don't want to mess with it now - the only possible hitch is it may report that there's a CD in the tray when there's none, which I can live with.
Now I need to fix the tray eject motor - it's sticky and needs to be pulled and pushed in manually.
Edit: I also used the opportunity to sand and spray paint the top cover, which was scratched and grimy with age. I slightly wet-sanded the outer surface to improve the adhesion of the new paint coat, rinsed it with water, allowed it to dry for ~3 hours, and then used an aerosol spray paint from a rattle-can. I used Flat Black colour from a brand called Cosmos Lac (seems to be imported from Greece), and it seems ok. However, Hacsol or Duplicolor brands may be better choices if available. If you're adventurous, you may experiment with alternate colours like Gloss Black, Bright Silver, Siemens Grey, etc. If you have a Champagne front panel, Siemens Grey would be a good choice for the top cover.