What chainsets are compatible with a Super record BB from 1981 ?

Your 1980 frame will have no incompatibility issues with modern parts in the following areas:

1. Headset. Fortunately, you can still buy 1" threaded headsets
   Ebay, forum, bike shops. issue solved.
   
2. Brakes. Modern frames use short recessed brake bolts whereas the old frames use longer bolts with those curved washers. You can still buy these washers, but longer brake bolts may be hard to get.
   Tektro and others make very serviceable longbolt brake calipers and Ebay or the forum sales. Issue solved
   
3. Rear dropout width is 126mm for 5/6 speed hubs. These use screw on freewheels rather than modern freehubs with cassettes. As long as your hubs are fine, you still get new freewheels.
   And/or new wheel set. Issue solved
   
4. Gears. If you are happy to stick with down tube friction shifters then you will have fewer problems. Almost any rear dérailleur will work as the amount of travel with each gear is controlled by you. Shimano introduced 6 speed downtube indexed shifters in the mid 80s. I have no idea if they are still available. Integrated brake/shifters came out later in 7,8,9,10 and 11 speed versions and you'd need the appropriate cassette, chain and mech for each version. And your frame re-spaced if you wanted to use them.
   Or use bar end shifters or those behind the brake lever units with the DTS brazeon adjusters/cable stops. If your frame is steel a few mm of cold set with fix the rear spaceing. issue solved
   
5. The bottom bracket is probably the only bit that hasn't changed much (for steel frames, anyway). A modern sealed bearing square taper BB will fit your frame just fine. [assume british] Shimano do them from about £10. I've bought a nice Tifosi one on eBay for £20. As I said above, any square taper chainset will do, you don't have to spend heaps of money. I have never found any discernible difference between chainsets labelled 8, 9 or 10 speed. I suspect it is just marketing.
   Not sure that "any chain set will do" get the best quiality you can afford
   
   

You will have to tell yourself often This Is all this worth it
fify