Since my first post I've been in contact with someone who restores hubs and pedals and he has confirmed what you suspect. He only restores things with good, inboard races. He's never asked his engineer to work on inboard races and doesn't know if it's possible but he's kindly offered to find out. We'll see but hope fades.

The Mikashima pedals you link are very good, without doubt. I have 2 pairs of their Touring model but I'm afraid that for me there's no substitute for the pleasure in using components that were made around the time I was born and have survived. Hats off to Mikashima, though! Inexpensive and well-made.

An aside... Mikashima pedals look much better if you polish them with 400, then 600 grit paper and then finish them off with Autosol metal polish. They look even better if you make an effort and polish out the casting seams.