Well, it's dear old Mum. Her favourite Bianchi is set up with drop bars and the old style quill stem w/wraparound clamp, a really short one. Think cruiser, upright bikes. She really likes the bike that way.
Mum don't like to honk up hills anymore, and can't be bothered to use the DT shifters often enough. Hence unhappy rider. But she isn't going to give up the drop bar any time soon.
So I'm thinking Brifters for her, and like to give her a modern (=sharp bends)drop bar while I'm at it - but these don't fit in her old stem. So I'm trying to source the shortest stem available with a removable faceplate to pull it all off - that is, let her keep the fit of the bike, while adding some more user friendly hardware.

25.4 vs 26.0 isn an issue. I can ream a 25.4 to 26.0 easily enough. BMX size would be a bit more tedious, but readily doable.

(and don't worry about the economy of it, I've got most of the parts already)