Fred: i'm not sure if they make any parts for the Emmert, but i just picked up a pattern makers vise made by American Machine and Tool company that is similar and it is similar to my Emmert pattern maker's vise.
here's a link to one guy that sells my AMT new and i think mine is maybe 50 years old.
http://www.highlandwoodworking.com/patternmakerswoodworkingvise.aspx
does your Emmert look like this AMT?
also since it's the internet you might not want to put in your phone # and email so you can go back and edit that out.
since you are a member you can get a PM (private message) from a member or we'll usually post the information so our threads help others later.
welcome to the group and can you post several pictures of your Emmert? i use the paperclip above where we are posting to attach sort of like an email.
have any questions or need help just ask and we'll try to if we see your question.