I need help I am doing research on a DC-3 and C47 and i have looked at the Maintance manuals and product lists but I can not seem for figure this part out. on many pictures there is what looks like a black rubber tube wraped around the fuel and oil lines. I need to know what this is and what the part number is or any information you might have. We think its a fire sleeve but doesnt make sence to only have short bits around the lines forward of the firewall. Any help would be awesome. my email is Fscheer@mac.com