I had a look at this area in Google Earth last night and where the artist has the wye in your drawing looks way too steep to have had train sticking out of it, but if you were to place it closer to the crossing in the open field, the tale track of the wye would only have dropped three or four feet.
The problem with the track chart is it shows the mainline running in the middle of Raquette Rd for about a block at this point, so it never helped getting an exact location for the wye.
Thomas, this is a very interesting drawing; thanks very much for sharing it. I had no idea that there had ever been a wye close to the Racquette Road. In fact, I'm surprised that it was still there as recently as 1936. My grandparents lived on the Racquette Road, almost at the corner of the Racquette and King St, and you can see their house just beyond where the wye begins.
Paul, I think that I agree with you that the wye, as shown in the 1936 drawing, appears a little larger than it actually was. In both the 1936 drawing, and in your depiction on the 2013 Google map, the wye begins just beyond my grandparents' house. However, in the 1936 drawing, the terrain is quite steep where it shows the end point of the wye. There are currently houses in this area that were built within the last 10 -15 years, and you have to drive up a steep driveway coming from the Racquette Road to get to them. The land where you have shown the wye on the Google map was formerly the Imperial Oil grounds and, as you point out, the terrain is fairly level there, and likely more suited for tracks. Therefore, I agree with you that this was likely the location of the wye, and that the 1936 version, while showing approximately the same starting point, shows the wye as coming out further down the Racquette Road than it actually did.
Also, you mentioned that it appeared that the mainline ran down the Racquette Road. In fact, the tracks crossed at the foot of King St and the point where the black arrow is on the map is actually King St. The Racquette Road takes a sharp left at this point, and King St branches off from it.
Why the wye in Digby? I you look in Gary Ness's latest book Digby had a turntable until the 1890's Page 16 and 17. Also a small roundhouse at that time. The roundhouse appears in this postcard no date.
Just a theory Andrew but the postcard is from the 1890s and by the time the 1936 drawing came out, it appears the roundhouse was removed. At some point engines went from short haul wood burners to longer haul and more efficient coal, making a roundhouse at Digby not necessary. Maintaining a turntable must have been more expensive then building and maintaining a wye.
Here's a question to consider... Truro had both a turntable and wye at the same time, here in Brockville they did as well.