Apropos of two stroke oil - Riders of veterans and other bikes with exposed valve gear like to use a drop of two stroke oil added to the petrol. This is to lubricate the inlet valve stem(s), which gets no other form of lubrication. When side valve springs are enclosed, a puff of oily smoke from the exhaust guide is sucked up the inlet guide, but when the valve springs and guides are exposed, the dry inlet guide gets no oil, and with wear acts as an air leak, so a bit of oil here via the incoming fuel charge is good. My M32 has felt hats between the valve spring and the stem, and the application of the oil can is called for now and then to keep things sweet. Whether or not these are original or not I don't know, but it was a common modification to try to keep grit out, and oil the valve stems at the same time.
Cheers for now
Doug