You could just go with some modern dual pivot sidepulls -and forego fenders and run narrow tyres, it might just be a lot easier. Just my opinion (so it's either a load of rubbish or fantastic depending on how you take it) but I think you might be trying to make the frame fit components it's not supposed to. I'd think for the money and time you might need to invest (thinking of brazing on posts, and then a respray), you could be better off looking for *that frame* that fits your ideas of what you want. Good luck!