The first loco kit I built was a DJH J50. It went really well, I painted it with I think halfords black, put transfers on then sprayed it with railmatch varnish. It bloomed terribly. It was so demoralising. I used nitromors on it and it fell apart (I'd used glue to build it). I forget what happened with it after that, I can't find it anywhere so may have thrown it away in disgust. It's a large part of why I walked away from model railways for 20 years, and why I've got a few bits ready to paint but to be honest I'm scared to do it.