geneb

I picked mine up at a commercial mower dealer (or you could try a place that sells home or pro lawn equipment). They frequently sell those accessories or can order it for you. You could also try searching the net for a "mower blade balancer".
I found that hanging it on a nail is not as effective.
For sharpening nothing beats a 4" to 4-1/2", 10,000 rpm right angle hand grinder. Get a coarse or medium metal grinding wheel and use a face shield (or at least safety glasses). It cuts quickly and you can take a lot off without burning the blade.

I have been using spray furniture polish on an older Simplicity and it works pretty well. Best to do before you blow and with dry equipment. Get some cheap cans at the market, make sure they are warm and spray the whole schmere. Let dry, repeat. Several times at least. Seems to last quite a bit longer than Silicon.