When I received this saw it didn't come with a carburetor cover or air filter. I looked at the IPL and it showed a different part number for the winter kit saw than the regular model. I located the correct number filter after searching for a few months. The difference I see is the winter kit filter is it looks like a poly mesh. Probably water proof if it ingested snow. Light will shine thru it also. 330 winter kit filter-1 by Clasec, on Flickr 330 winter kit filter by Clasec, on Flickr 330 filter comparison by Clasec, on Flickr
I wish I'd have known you were looking for an air filter for your 330.I bought mine last yr.from Bob Johnson for $12,but no one wants to listen to me when it comes to buying parts from Bob.
I put Bob's number in my folder after hearing you post about him, but I didn't think he would have the winter kit numbered one. I'll have to give him a call. It doesn't hurt to have a spare if he does.
I had some time to work on the collection so I put a NOS drive case cover bar and chain and filter cover on the 330. Waiting on the air filter cover screws and knob. Its getting there. 330SL w/winter kit by Clasec, on Flickr