Newbie To The Group - And Yes, A Few Questions!...

It's great to see you found this set. I can remember back around that same time running on Aurora AFx. You will most likely be able to find a power supply on one of the typical sites like ebay, facebook marketplace etc. You could get new controllers and for what you might want to do you may want to just check out AutoWorld Slot cars. www.autoworldstore.com . I haven't done anything with my H.O. scale slot car stuff for several years so beyond that I'd say AutoWorld is your best bet. Even going to them you will find the terminal track won't click-in to the 1973 track. Way back in the day there was an adapter track but again you may end up on an auction site to find that adapter track.

Your other route may be to check out someone like Professormotor.com . They have some great controllers of a very high quality. you could also just DYI a terminal track with some wire, solder and controller you manage to find. Though you could also just buy a small set (H.O. Scale or 1/32 Scale approx $150US) with a couple cars, controllers, power supply and re-enter the hobby that way. There again I'd look at Autoworld. Often you can find Autoworld slot cars and sets in a hobby store like Hobby Lobby, Hobby Town etc.

Good luck and welcome back to the hobby.

Welcome @I_Was_A_Kid, you'll find a lot of knowleadgeable people here. For your specific questions I think you'll get more help if you post this in the HO forum.

From the diagram you posted and the date I think you have an Aurora Speed Lok track, from what I've read it's very problematic as the tabs that lock the track pieces toghether tend to break easily and I think that electrical contact between ttack pieces is an issue too. I think the best choice would be to buy the newer AFX/Tomy track that is also compatible with AFX/Racemaster and AutoWorld track.

If you want to use what you have you could search ebay for a speed lok terminal piece.

As for the power supply, the best choice would be to avoid the original power supply as they were not very good and provide too low amperage. You could use a newer AFX or AutoWorld variable power supply, a laptop 12V-19V power supply or a $50 variable DC power supply from Amazon.

As for the controllers, most people prefer third party controllers and say it's the best investment they've made. If you don't want to spend much, you could look for AFX "Russkit" controlers, they are much better than modern set controllers and can be found for around $15.

Oh, and post photos of your cars, we love old miniature cars photos.