I see you have managed to buy yet another shade of Russet brown! Nice work though mate, takes courage to take on that panel with nothing more than a sheet of steel and a pair of tinsnips!
Don't be upset about the colour match though, I'm convinced that every Russet car is a slightly different shade (sometimes several slightly different shades) there are at least 6 factory shades, then there is fading, cos Russet has a lot of red in it! When I used to paint, back in the day, I only ever ordered 1/2 a litre of Russet, cos I knew that by the time the paintshop had finished tinting it to match, i'd have enough to paint the whole car!
I've found telling myself it's a customers car helps when cutting big holes in the body work otherwise I would never have the courage to do it! Just got to work my way round the rest of the car now. I'm not fussed about what shade of russet brown at the moment coz it will have a complete respray at some point.