Unfortunately I don't know everything, far from it, and this particular post has proved problematic. My knowledge of autochanger Philips machines from the Disc Jockey era is one such grey area and, despite asking for assistance in the forum, nobody offered to help. I'm therefore limited to providing a couple of links, as per below, which will hopefully be of help:
https://www.vintage-radio.net/forum/...ps+disc+jockey
https://www.vintage-radio.net/forum/...ps+disc+jockey
Other information is likely to be found via forum and web searches as well as from service data, when/if available.
There are nonetheless a few points I can add. That now-troublesome rocking pickup head was also common on autochanger machines. If these need rebuilding or replacing with the still (at the time of writing) available substitute, the autochanger tonearm does, or usually does, have provision for tracking weight adjustment.
Beware. The replacement head mentioned is, usually, the GP235 which at the time of writing has become ridiculously expensive (£50 new, give or take, but shop around). Therein lies the main drawback with obtaining these machines; my own advice to anyone tempted to purchase one is to first check that the cartridge is still good before purchasing if at all possible. Whilst accepting that safety considerations are paramount with old electrical equipment, if the vendor of a Disc Jockey says "Nah mate, can't plug that in - it's sold as seen" then either steer clear or be prepared to pay repair/replacement parts bills totalling a lot more than you've probably paid for the record player. This of course applies to any Philips machine, be it auto, single play or add-on, which uses that pesky 'rocking' pickup head.
Idler wheels were, perhaps not surprisingly, peculiar to Philips are are now virtually impossible to replace. So if your tempted to obtain one of these machines then be wise and attempt to ascertain it's working condition first; a disappointment here is better than a lot of hassle later having purchased the machine blind.
Fortunately, once out of the Disc Jockey era Philips produced somewhat more conventional offerings and problems with these are broadly relevant to other posts in this thread.