Hit Welcome to GJ. That is a nice restore job. As you might have found in general it is not easy to find parts for old vises. Some of the members here such as Dr. Scott (
KMSCOTT) make high quality parts for higher end vises but I do not think for Columbians.
On ebay there is a seller that goes by the name
oldtoolnut59. He often has parts for various vises. He is a good guy and is always helpful and also his prices are very fair. You might want to contact him through his ebay store.
https://www.ebay.com/usr/oldtoolnut59?_trksid=p2047675.l2559
Panch I believe one of the members here namely
autopts has access to genuine Wilton parts and I think he also sells parts on eBay. And if I am not wrong this includes swivel basis. You might want to PM him and see if he can help you.