Originally Posted by
FastJake
I may have missed it with the lengthy posts, but what do you have against buying a new 1" threaded headset to use with your fork and threaded stem?
The OP wants to use a 31.8 mm handlebar and 1" quill stems with that size handle bar clamp are pretty much non-existant.
I would suggest just replacing the current pitted headset with a new threaded one. Then you can get a "threadless stem" adapter that looks a lot like the item you pictured in your first posting. That will let you use any threadless stem and matching handle bars.
I wasn't ridiculing you but the consensus here was that your first proposal was unsafe and not recommended and you didn't want to accept that conclusion.