I'll let you know if I find something - DH and I have needed to replace some rather odd connections around the farm and had to get most of them online. The pictures of mine look in worse shape than yours. I could always patch and re-cut the hole so the Singer one fits. I love vintage, but will not hesitate to upgrade electrical.
BTW - the screw that held the motor on my New Home K is the same thread as what the W9 takes - but a hair smaller in diameter - my husband is going to measure the screw and I'll tell you exactly what it is. He's got one of those thread feeler gauges. He found a site online that has the 4-48 screws I need for the tucker that fits the Davies NVF but it requires $15 minimum order, so I'm going over my other attachments and figuring out screws/nuts I need. May not be pretty like the original, but it will make them functional.