Hi, I facing a similar situation with my layout. in the past I have drawn plans as part of a possible built based on the the enclosed image taken from here:
https://www.google.com/url?sa=i&url=http%3A%2F%2Fivybridge-heritage.org%2Fthe-south-devon-railway-and-ivybridge-train-station%2F&psig=AOvVaw3ihItghe01K-PC0bEsG2X2&ust=1615978881348000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCKibvM7UtO8CFQAAAAAdAAAAABAJ
I'm sure I still have it on my computer, will look for it. There is more information on the site one partial photo of the goods shed sufficient to come up with a general shape. I decided to go on a different route.