I have a Mac 10-10 that has a similar issue, specialized fuel filter, but I am missing the components for it, I just have the fuel line. It was recommended to me to take a regular fuel filter and connect it to a short piece of fuel line and just insert that fuel line in the Mac fuel line. Might be a temporary fix for you until you find what you need. My Mac D-44 has a felt fuel wick about the size of a 4x6 card, I ended up ordering it from Mark
@Hinerman . He may have some of what you need or might be able to help you find suitable sub material. Felt erasers may work, but might be wise to test it with fuel before installing in the saw, you don't necessarily want to go through all the trouble only to have it fall apart and clog everything up.