Several offices have moved in recent years, but are still on maps or traffic signs in the old locations. Old and new locations given where I know. In addition, some are on wrong location in google maps (corrections submitted).
I will visit more and take pictures, finally can call the post: Pictorial guide to TAT offices in Thailand (there are some abroad as well).
Some are in houses obviously erected for being a TAT office, some in interesting architectural styles, others in nondescript buildings.
See here as well:
List alphabetically by their English name (Phra Nakhon Si Ayutthaya filed as Ayutthaya), data from http://www.tatnews.org/tat-local-offices/ slightly edited.
600 m west of MRT Phetchaburi. TAT sign on side of building can be seen from far away.
3. TAT Chachoengsao Office
I have been to the temporary office.
6. TAT Chumphon Office
7. TAT Hat Yai Office
I have been in Jan 2015 but didn't take picture. Update 2sep2017:
8. TAT Kanchanaburi Office
I have been, but can't find the pictures. Take new on 29dec2017:
9. TAT Khon Kaen Office
Tourist Information Lampang Municipality
Sop Tui, Mueang Lampang District, Lampang 52100
small office, but real branch is 50 m N of ห้าแยกหอนาฬิกา
สำนักศิลปากรที่ 4 ลพบุรี The 4th regional office of fine arts Lopburi, and moved to 14.799985, 100.651173 = 14°47'60.0"N 100°39'04.2"E on the grounds of Lopburi City Hall ศาลากลางจังหวัดลพบุรี (NW corner of Narai Traffic circle).
I have seen it driving past on bus.
16. TAT Nakhon Phanom Office
TAT Nakon Sawan
1045/2 ถ พิษณุโลก ต อ เมือง Wat Sai, Amphoe Mueang Nakhon Sawan, Chang Wat Nakhon Sawan 60000
Visited 8nov2017, and staff told me it has been open for 8 months and I'm the first foreigner to visit them.
18. TAT Nakhon Si Thammarat Office
I have been in Aug 2014 but didn't take pictures.Update: visit on 11oct2018:
Hwy 4084, southern side, out of town directly after the bridge.
20. TAT Pattaya Office
I have been many times, and taking another picture next time I go is faster than searching for pictures I took in the past. Update 16sep2017:
I have been in Aug 2015 but didn't take pictures.
(I took frontal pictures from middle of road on another visit, just can't find it!)
28. TAT Samut Songkhram Office
Used to be next (SW of) to Phra Ruang Bridge, and on old maps still old location shown. Now at 17.009003, 99.810554.
Picture take 24sep2018, visited 25sep2018:
14°28'27.4"N 100°07'04.3"E = 14.474286, 100.117870
on the grounds of ที่ว่าการอำเภอเมืองสุพรรณบุรี
32. TAT Surin Office
33. TAT Tak Office
7.551704, 99.610149 = 7°33'06.1"N 99°36'36.5"E
35. TAT Trat Office
36. TAT Ubon Ratchathani Office
37. TAT Udon Thani Office
38. TAT Uthai Thani Office
Visit 6apr2016 and again on xxx:
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