Sorry to be out of the loop.
The three holes across Excelsior date to the original 9-hole routing that opened in 1899 with William Watson, Robert Foulis and Minikahda member/founder Clive T. Jaffray taking design credit. At the time, this part of Minneapolis was in the hinterlands and the the road was single lane and dirt. Through all the routings, the first hole has always been the same. Originally, golfers then crossed over and played today's 15=17 as 2-4. The fifth hole was odd. The tee was roughly to the right of the existing 15th tee and the green was where the sod farm is now. Players would finish the hole and walk back to the tee, recross the road and play the sixth, which is roughly today's second hole.
The course was expanded to 18 somewhere around 1907 by the Minikahda head golf professional and Jaffray. The routing, I believe, turned the holes across the street into 14-17, although there was talk of them being kept as 2-5. In 1908, Thomas Bendelow arrived for a complete redo of the course. He kept the four holes as 14-17. On page 34 of "The History of The Minikahda Club Golf Course" there is a map of how the Bendlow course might have appeared. The Donald Ross hole-by-hole drawings show many existing features and the notes talk about them, as well. Tim Gerrish did a fine job creating the drawing.
Ross eliminated the weird par-3 on his 1916 plans.
Ross's 15th hole was much more of a dogleg. When Excelsior was expanded, the tee was moved away from the road. The green was also rebuilt but I don't think because of the road widening. I believe that the 25th anniversary book talks about a new green.
On the Ross drawings, 17 of the greens are detailed, but the drawing for the 15th is odd, almost a perfect diamond shape as if he forgot to finish it.
My understanding is that the new book is available in the pro shop.
I hope this helps.
If you need more, AnthonyPioppi@gmail.com.
Anthony