i agree with you about these saws. they are good saws and very reliable. by today's standards they are heavy and slow but for the price that you can find them...why not have a few of them. you can have a 60cc saw with 20" bar for less than $100 and they usaully show up for work every time you pull them out.
Looks like you have the older thick ring version. remove that spark screen and back out the oiler screw. if you take it all the way down, you can open the exhaust port and really improve the power. it makes a big difference.
Older, like made in the USA. I have one of the newer ones with a sticker on it that says "made in Mexico".