There is a large group photo of the officers of the 135th that was taken at Toul late in the war (or just after?) that is reproduced in Gorrell M.17 that includes Drummond. There are no ids in Gorrell, as far as I can tell, but the same photo is reproduced inside the back cover of Lawrence L. Smart's The Hawks that Guided the Guns (privately printed, 1968), and he offers ids. According to Smart, Drummond is 5th from the right in the back row.
Unfortunately, the Gorrell print is not high quality: perhaps someone has an original that could be scanned at better resolution.
I can try (later in the day) to upload a copy of the Gorrell photo, in case you can't access Gorrell at Fold3.
https://www.fold3.com/image/311370964 (behind a pay wall).
best,
---Marian