Replacement high speed valve is different. Mine has a flat adjustment hand and the new one has has a slot screw head. The old one didn't have washers or o rings. I assume that the replacement for that packing nut goes in the body first then the o-ring, then washer, then spring and needle valve. Is this correct? Also, what is the tiny nonmetallic washer with the very small hole for? It is too big to be a seat for the need.