I have painted over 600 brass models in my time... For good or for bad my worst mistake was on my own cars. Maybe 10 years ago I was putting the glass in 4 P70 coaches (meaning they were DONE) when a friend noticed I flipped top to bottom the single and double stripes - on ALL 4 cars. I had photos right in front of me! Brain fade city! I just sank in my chair. A week later they went back into the box until late last year when I dug them out for the much better than before redo. All I need is time to finish them! I also was designing and 3D printing some trucks for the hot cars.

I have had 2 redos for others including 1 for a wrong number - missed it by 1 car.

In my early days of painting, before anyone made reading yellow or green, I mixed a slightly faded reading yellow. I used 6 different floquil colors and came up with a perfect yellow. I sprayed a GP-35 for a friend. I was so much in a hurry to apply the green, I put the shell over a lamp to dry faster. A phone call later I came back to find a hump back 35. and I didn't write down the formula for the yellow. Good thing shells didn't cost then what they do today! never did get that perfect mix again.
and I do agree my best work I have done for others, and I got the defects.

Another time I was asked to paint a lionel caboose LV cornel red. I told him I knew Reading stuff better. I was given the paint. I looked in all the books I had and this color didn't look right. I know that color is the topic of many a debate. So in my dark incadesent lit room I mixed the paint and sprayed it. It looked more like the pictures. and I was happy I then decaled it. When it was done, I took it to the hobby shop for the customer. When I took it out in the sunlight It looked purple! Arrrgg!!!. The customer of the shop was not happy. Years later When I got my real caboose a guy stopped up and quizzed me about how to get one. He took measurments of mine and we became freinds he did get a pennsy caboose and has a garden layout around it. He past away a little more than a year ago. When I was cleaning up my attic train room I came across the mixed bottle of LV paint under a rubber band was the name and phone number of the consignee. It was my friends name. I never knew who I painted it for. Good thing he didn't get me to paint his PRR caboose. He's probably up there Laughing!