I have not taken a 1936 206 apart, so my thoughts on that "screw" are just my opinion ...but I thought that it was a external "set screw" used to fasten the upper oil pump housing. Others here may know better than me. That "screw" and the combined oil fill/draft tube on the driver side is a qwik way to spot an early 206 versus latter 216's. I will shift my future responses to the Engine shop section.
