If it were mine, I'd file the binder lugs off smooth. I'd find the appropriate slip over binder clamp. The taller and wider the better (meaning more grindable material). alloy is going to be easier to work and you want to try to match the silver lug. So try to find a silver seatpost clamp. The upper, inner stop of the clamp can be filed off (so it can slide down freely) and then you can SCRIBE it into the lug after you have marked out the material to be removed off the bottom side. I would use either a grinder or file and a vise. Hope that makes sense as a tutorial on scribing would be exhausting.. I would then epoxy the custom clamp right onto the lug when I was confident it would work and look as professional as possible. I believe I could make one that would look like the bike came that way new. You could also match the topside of your custom binder to the lug contour. it's trick.. but doable and highly recommended so as not to over stress the front tip of the lug. There would be more bite on the front that way too as it would sit more naturally on the tube- like a saddle essentially. Any framebuilder should be able to make one very easily as that is essentially how they fit tubes in a lugless design. speaking of, you should ask over there too..in framebuilders.