Mostly I am selling older gear on eBay and need line cords for them. Besides HP, Wavetek also used them.
Having the wrong pin sequence is only a possible problem for internal service. And unlikely to be a big deal.
I believe the above Orion model 28131-76-01 cross reference above is bogus. My search showed this to be a plain old seven foot IEC cord.
Marlin Jones had some of these at $4 but sold out before I could buy them.
I'm wondering if a line cord could not be terminated in three Molex terminals and then backfilled with polyethylene out of a glue gun.