I know your problem and I still have an old 36MHz Tx and a few Rxs here but to be honest you are seriously better off just biting the bullet and buy a newer radio system. Sure you will find some are so high tech that they can require almost a uni degree to set them up but then others are so smart that they are logical and easy to use.
If you buy a new system just get one that has a dual antenna Rx as the radio signals do not reflect as well at the higher frequencies and polarisation losses can cause crashes with a single antenna Rx. I use the Turnigy, (HK version), of the FrSky iA6 (6 channel radio) and the Rxs are so cheep and the radio itself so inexpensive that you could basically buy one for the same price as a single or a pair of 72MHz Rxs assuming you could find them in the first place. With a range which maxes out at around 1K it is quite suitable for all but the long range and high altitude flying.
I now have 20 Rxs to go with mine and about 25 planes which I fly.
Programming is possible but it actually more like just setting thins as you want them. You can use its full features or just as you did on your original system. The radio has the ability to support 20 different models and so all of the trim settings, channel reverses and the like are remembered for each model slot. No more need to adjust or recentre trims between models and a lesser requirement to infinitely adjust the model control surfaces to enable the trim levers to be or remain centralised.
I started over 40 years ago myself and I really DO NOT miss the limitations of the older equipment but I am not a fully wrapped up in the tech for its own sake. To me the enjoyment of flying is more important than the ability to fully exploit every feature of the radio systems.
If you wish to continue with the old gear I wish you good luck in finding compatible Rxs at a good price.
Have fun!