Jerry I think your answer as to why Banks was contacted can be found in the 1927 (I assume this is from early 1928?) annual report you posted,
“On recommendations of Chas H. Banks, Golf Architect, partner of the late Seth J. Raynor, who designed the course, work was started for its completion, as originally laid out by Mr. Raynor. The Board of Directors appropriated $1,200 for the necessary improvements. The sum of $570.00 was used in such work during the fall.”
It seems to me that work was being done on the course to Raynor’s plans through 1927. As to why Banks changed the plans? I really do not know unless money was getting tight through 1927.
I think it is important to remember that Charles Banks was Seth Raynor’s partner while Raynor worked on Blue Mound. Any changes suggested by Banks were likely inline with Raynor’s plan. The 1924 drawing is more of a proposed conceptual drawing that was meant to give the members an idea of what the course is going to look like. I don’t think they were trying to follow the conceptual drawing to a T because it just wasn’t detailed enough. Many of the greens are shown as rounded squares rather than Punchbowls and Road hole greens. It was a general scheme, which only becomes detailed when you read the description of the holes.
Banks drawing are great, but many of his drawings are also very generalized without detail. If the hole was O.K. (according to Banks), he didn’t bother drawing in the existing fairway and green side bunkers. The only holes he shows any details on are the holes that appear to be unfinished, or the holes he was making suggestions on. My interpretation would be that Banks was trying to finish the course to Raynor’s plans, but helping the club with the location or placement of those bunkers. I feel like Banks also offered a few alternatives that would have likely made the course harder, but the club didn’t appear to take him up on many of those suggestions.
If you look closely at the 1927 aerial, you can see that certain holes are in different stages of development. The original 10th and 11th hole have very patchy fairways, which looks to me like they are still growing in. They also do not have fairway bunkers but the greens are completed and bunkered. Other holes such as the original first and second look like they have been in the ground a little longer with their healthy looking turf and fully bunkered fairways and greens. The original 9th has a patchy fairway but is fully bunkered. I think the aerial picture shows us how developed some of the holes were compared to others.
After looking at the 1937 aerial, it appears many of the bunkers Banks suggested on the unfinished holes were implemented. For example, his recommendations on the original 3rd, 6th, 10th, 11th, and 14th were carried out. In some instances they may have replaced a suggested bunker with a grove of trees? On the second to last page of the drawings there is a little chart that shows a handful of holes that they deemed O.K.. Next, they list the 2nd and 5th hole as changes to be made in 1928. The third row they list a handful of holes for 1927 and a few holes under the category 1927 Minor changes. The 1928 numbers are written in black ink versus pencil and you can see a few black ink check marks next to the bunkers the club appears to have implement by 1937.