[humorist2751]

Tas:

As promised, a scan - cut into chunks for size limit reasons - of the Cummins article appears below. A well-stocked scraps box may well already contain most of the components, but when I applied the mod. to my own set I could not trace a diode of either of the two suggested types; I used a BAV21 instead, which appears to function perfectly well in this circuit.

The best of luck to you with your own efforts!