30's-40's Chevy window channel rollers (replacement)

I'm replacing the glass in my 36 Chevy 2 door and have ran into a problem. The rollers that slip into the C channel are missing, or not much there. I have seen these rollers on other projects and look to be a semi-hard rubber type. I have also looked through the DOORMAN catalog and could not find anything that looks like will work. The rollers are about 1" dia. 1/4" thick and slip over a mount. Has anyone found, or used somthing from a hardware store, that may work? Thanks in advance.