William Sommerwerck wrote:
I know I'm not directly answering your question, but...

The socket and power cords are polarized. It would be extremely
difficulty to insert the plug the wrong way.

Thanks for the reply. Yes, I expect that reverse voltage
protection would be a secondary consideration. Its primary
function would be protection against over-voltage, transient or
sustained. Something like a crowbar or TVS device, but without
the need for very low capacitance. A datasheet or identifying the
manufacturer would be a big help.