Having seen the horrendousness that is the TFL fares section, I can't
tell if National Rail-railcard discounted paper travelcards are still
available.

My parents (one Senior Citizen railcard-holder and one Disabled
Railcard-holder) are coming for their first trip to London for years. I
don't want to have to educate them in how to use an Oyster card, when
they know that you either show your paper Travelcard to the bus driver
or put it through the gates at the tube station.

Are the still National Rail-railcard discounted paper travelcards?