The problem with the aerosol paint is that it scratches very easily. I had a new deck cover bent to replace the original one when I added a blower and had to shorten the lid, then used a spray can from Grasshopper to paint the lid, it looked good for a year or two then it started to look scratched up as the paint never seemed to get as hard as factory paint. I agree it all depends what your expecting to get from the paint? if its long term, mixing and air spraying commercial paint is the only thing that will hold up plus they have computer programs that look at your color and can then mix a very close duplicate color.
POR 15 is the only stuff that will stand up to the punishment of mowers.
Once cured bullets bounce off it.
The only thing that touches it is UV so you brush it onto bare or lightly rusted steel and it is on there for good provided you top coat it with something .
No matter what yo touch up your deck with, it will not match the original which will have started to fade.
So you colour match it today and next year it will stick out like dogs dangles because it and the base paint will be fading at different rates.
The only way to make an "invisible " touch up is to repaint the entire deck.
The mower is a tool not a work of art.
It s going to get scratched with use no matter how careful you are
