In 2040 we might have neural link or brain waves shifting, who knows If I'm still around then, I think I will be still happily using Suntour derailleurs with friction shifting.

Looks like I found Swiss IRD cups in a shop within the EU. So I'll get a set just in case whilst I'm trying to figure out a spindle. Combined with checking whether any Miche or Tifosi cartridge type bottom brackets are compatible. I have Sakae Ringyo Royal in 112 on its way, though I expect this won't be the correct fit for the cups I have as it's not from a 70mm BB. Other ideas to try are Sugino MW-70, though that is 114mm, and Campagnolo 70-SS, which I think can be 111 or 115mm.