I like this project a whole lot. The building would also make a decent old time garage with some Model Ts hanging around.
I agree with the dimensions etc posted here. I'd start with a scale sketch of the front, based on the size assumptions posted. It would be helpful to have a 1/25 scale ruler so you don't have to convert dimensions. Once you have established a proportion scale from the doors, it will help you determine the rise of the roof (the front peak) and the size of the upstairs windows. From the two photos it appears that all the windows (except for the side basement one) are the same size. So once you know that size, you can plot out the length of the side from that window placement. Also, note that in the front photo you can see straight through the second floor and there is a window on the back. So I'd assume the same window pattern on the other side, and the upstairs of the back. There would be no back or side door from the first floor due to the slope. But somewhere there would be an entry to the basement.
If I still had access to AutoCad, I'd do a quick sketch in scale for you, just out of my own curiosity. Good luck with this project, we'll all be watching!