I've had my toy for 5 years. It's a 2004, had 435 hours on it, I have about 1500 hr on it now. I have rental property. Use it for yard work. Love it. Wish I had it years ago, perhaps my back would be in better shape.
I get my cylinder parts from Terramite, $30-40 to rebuild depending on which cylinder. Never heard of McMaster-Carr. I'll google it. How do I know what part number to ask for? When I talk to Terramite, I give them my model number, tell them which cylinder and they send it. Takes a day or two if it's in stock.