Mike
That sounds a little bit like a 'how long is a piece of string' question. I see you are in California, there are so many questions to be answered. What country is your railway set in, if the US, what part of the country. I imaging shop fronts in California are different to those in Colorado or Maine. What era, old time shop fronts or modern glass and steel. Time of year, for example, shop fronts will look very different on the run up to Christmas. Are your shops part of a big city or a small rural community. Good luck with your search and remember the Golden Rule on this Forum, we like photographs.
David