Nice work!
To the OP - vintage bikes are old frames with many potential uses, including restoration as well as conversion. What's so wrong with tailoring one to fit the needs of its owner? There are plenty of bikes to go around, and many (heaps) of original examples out there for those of us who desire to have one. I don't think the world's supply of vintage frames is going to dry up.
I'll post pics of my Marinoni here -I'm assuming an S3X qualifies- when it's done (2 weeks out). I'm fabricating a SS bracket for my porteur rack this evening (waiting for my 12V dremel battery to recharge - ugh).