The many subdistrict creations announced in 1947 include several cases where the names used in these announcement differs from the current name, but without the renaming ever announced in the Royal Gazette. A complete list of the name changes I found would be way to lengthy for the blog, so I only pick a few examples which show the different kinds of changes which happened.
The first one is the obvious one, the name changed but without explicitly mention it. For example, in Ranong the subdistrict La-un Nuea (ละอุ่นเหนือ) was split off from La-un (ละอุ่น). But additionally to this La-un was probably renamed to La-un Tai (ละอุ่นใต้), at least that is it's named now, and it makes most sense to happen together with the split. And the same happened with neighboring Bang Phra (บางพระ), where also the northern part was split off and the southern part probably got renamed simultaneously.
There are also subdistrict spellings which I suspect are simply misspellings, as the whole announcements were written by hand these might have slipped through. For example the subdistrict Krado in Yarang, Pattani, is spelled กระโด nowadays. In the 1947 announcement it is however spelled ปะโด (Pado), maybe in fact it was simple a spelling change from กะโด, only the R (ร) letter added later. One case where I have proof of the mistake is Lathai, Kanthararom, Si Sa Ket. This one is spelled both ทะลาย (Thalai) and ละทาย (Lathai) in the same announcement, so the first occurrence must have been a switching of letters. Or Khlong Khut (คลองขุด) in Mueang Satun district is spelled ลองขุด, simply omitting the first letter.
Already mentioned in the previous paragraph, in several only the spelling changed, which kept the name phonetically same or at least close. There were probably several smaller spelling reforms, not as drastic as the simplified spellings used 1942-44 but still noticeable. For example when Rahan (ระหาร) became Lahan (ละหาร) in Bang Bua Thong, Nonthaburi this was probably an adjustment of the spelling to the actual pronunciation; funnily the word Pho (โพธิ์) in Pho Talad Kaeo (โพธิ์ตลาดแก้ว) changed spelling to the simpler โพ, but in Pho Rang Nok (โพธิ์รังนก) the old name had the spelling โพรังนก. Another example where a silent letter was omitted in Kaeo Chan, which changed from เกาะจันทร์ to เกาะจัน.
In all of the above examples it is easy to match the spelling in the old announcement with the modern spelling and thus identify the subdistrict. While I believe I could correctly identify all the subdistricts mentioned in the 1947 announcements, there were a few cases where it was very difficult. In one case after the search of the 1947 subdistrict I noticed that in fact I even misidentified that one in a later announcement. In 1947 the subdistrict in Mueang Udon Thani district was named Nong Bu (หนองบุ), and it was renamed to Nong Na Kham (หนองนาคำ) after 1974. Due to the similar sound I misidentified it with Nong Bua (หนองบัว), but actually Nong Bua was split off from Nong Bu in 1947.