Does someone have a supplier and pn of an air filter that will fit the round filter housing (not oil bath) for a 216/ 235?

Here is the housing:

http://i.ytimg.com/vi/vszqezZpNTg/0.jpg

The original was like a steel wool/rats nest type of material.

Would like to use a paper filter, but want something that wont be too restrictive since it is a pretty small filter.

1950 3100 Project-just getting started