Thanks for your response.
Possibly the French and Canadian postal authorities are more relaxed than Royal Mail. Or did you have problems at the Canadian end? It's not as if the French company is completely unaware or disrespectful of postal regulations. Their web site makes it very clear that they will not ship aerosols. In any case they did ship my paint and it did get to me.
This is essentially touch up work although I have removed a significant dent from the boiler shell and so anticipate completely repainting at least this part of the model. I don't have any other items requiring this colour. At the very most I need enough paint for a complete repaint of engine and tender with a bit left over for future touch ups (i.e. not a great deal).
I've had the auto shop option recommended to me before, but gave up on it because I was told that, due to Ontario regulations, the type of paint I'd get would not be suitable. Here I must admit to being unsure as to just what kinds of paint are suitable for a live steam model. Obviously I'm not about to walk into a home decour shop and have my colour made up in eggshell latex, but beyond this I'm at sea. Are acrylic paints a reasonable choice?