Holley 1920 rebuild kits?

Funny story. I went into my local O'Really's parts store and asked for a rebuild kit for the 1920 on my '72 and they shared that "huh" glance and took 15 minutes trying to find the right book to even begin looking it up. I love throwing these guys for a loop with the slant! Sure enought they got it in for me the next day (today). Cost me 20$. Any ideas on the best way to clean all the soot off the orig? Elbow Grease?