When I was looking through some very old announcements in the Royal Gazette, one on the 1915 relocation of the district office on Mueang district in the no longer existing Thanyaburi province lists the previous location as being within the subdistrict Khlong Soi Thi 10 (ตำบลคลองซอยที่ 10) [Gazette]. By using the search function with the Gazette database, it seems the "soi thi" (meaning "branch number") was dropped from the subdistrict names in 1919. The same function also returns that there were subdistricts which had some additional words after the number, e.g. ตำบลคลองซอยที่ ๑๓ ฝั่งตะวันออก (Subdistrict Branch Canal number 13 east side). Sadly I have no complete list of subdistricts of that time, and also many of the subdistrict renamings back then were not announced in the Royal Gazette, so I have no overview how many subdistricts there were originally with this naming scheme.
|Map of Rangsit area, source|
Tough it focuses more on the irrigation plans for the western rim of the Chao Phraya, the book King of the Waters: Homan Van Der Heide And the Origin of Modern Modern Irrigation in Siam by Han Ten Brummelhuis gives a great overview over the agricultural expansion at the beginning of the 20th century, of which the Rangsit area was only one part.