I'd consider buying a couple more for future spare parts but I reckon my GF might kill me if I bring another mower home
Don't do what I and others have done and allow a collection to begin. It's like eating Pringles, once you start you can't stop! Just enjoy and appreciate that unit you've got and buy parts as required, new or second hand. If you do come across another, whatever you do, consult your girl first. Happy wife happy life.
Regards the blades, I would recommend not to sharpen them as you could take too much off one or more and upset the balance as they spin and you get a lot of centrifugal mass and any imbalance gets compounded at the high speeds they operate.
They will cut fine as they are. It's normal for them to not be razor sharp when new. You're not shaving with them. The high speeds they're moving (even at idle speed) will cut the grass fine. Just replace them when they're too worn or are damaged. That's enough.
As for the blades being immovable, try loosening the nut a little at a time until you are able to move it a few degrees with your hand. You don't want them too free and loose.
Disconnect the spark plug lead before working on the blades. You don't want it to start up from turning the disc. You will never have the reflexes to move your hand away in time!!
