I had a similar problem with the fuel petcock on the 175 I'm putting back on the street. A piece of brass tubing from a hobby shop took care of it. In dealing with the filter screen, I used a piece of brass screen I purchased a while ago on an order of various items from McMaster-Carr. I happened to notice they had brass screen, so I ordered a 12" x 12" piece of 100 mesh for $7.48. It makes perfect screen for fuel petcocks and oil tanks. It is more than enough to last the rest of my life. Next time any of you order something from McMaster, it is worth getting a piece of brass screen just to have on hand. Plus, they have just about any mesh in many different materials, including stainless, at very reasonable prices. I used to go to the auto parts store and scrounge around until I found a lawn mower or auto filter that had a big enough piece of screen that I could cut up and use.