using new technology on old machines

Actually, no. That honour goes to the PSU in a Zenith MDA monitor which as I said 'combines the efficiency of a linear with the reliability of a switcher'. The design (if you can call it that) of this PSU is to rectify the mains, feed it into a free-running chopper circuit, then a transformer. The output of that is half-wave (!) rectified giving about 18V DC. Note the chopper free-runs, so there is no regulation applied at this point. That 18V is then fed to a discrete-transistor linear regulator. And that's not the end of the 'curious' design. As you know, a linear regualtor compares the output voltage of the supply with a reference votlage. That reference voltage is typically produced by a zener diode. Not in this monitor. It uses the drop across the power-on LED. Which means it is important to use a green LED. Another colour, with a different Vf, and the PSU output is wrong.