If the parts are stock, the long black AF cover and 1/2 wrap handle would be a 300. 87cc model with no automatic oiler. It could also be a 380, also 87cc but with an automatic (pulse) pump for the oiler located in the fuel tank.
If you can put your hands on the saw, turn it over and look for numbers stamped on the bottom of the crankcase. The same block could have been used on a 650 (gear drive), but this one was turned into a 300 (direct drive) Serial number 13802.
Assuming it has decent compression, it would be worth $100 if you didn't already have one and want to have an old McCulloch front tank saw...