I agree that that ideal location for the Kingfield car shop would be Phillips. However, since they currently have their hands full, if the building is in danger, etc. it might make sense.
I did not realize that the Kingfield car shop was that small. Of course we could just extend it to make it long enough for a whole train. But then we would be back to a 2-track design (which was what was originally proposed for Sheepscot.) Since the building has already been modified, adding length would not destroy any "historic fabric".
I think it is worth keeping an eye on. With the land for sale, the building could easily not fit in with whatever the new owner has planned. Also, in some cases, land is more valuable without a "potentially historic" structure on it which could make development tricky.