This is an old Chinese Tai dictionary, and I know its a Tai language but I don't know the specific one. Is it Shan or some other Tai language?

https://archive.org/stream/02076757.cn#page/n2/mode/2up

This appears to be yet another Tai language-

https://archive.org/stream/02076759.cn#page/n2/mode/2up

https://archive.org/stream/02076760.cn#page/n2/mode/2up

The first one, in file 02076757.cn, is in a northern script of the Thai family. The Fakkham and Tai Nithet scripts come to mind, but that's because I'm focused on Northern Thailand. The likely languages are Northern Thai and Lao. I'm not sure about Tai Lue - I don't know how much success the Thai script family had in Sipsong Panna, where the present-day scripts are the Tham script and its derivative the government-sponsored New Tai Lue script, which belong to the Mon script family. On facing pages I could read temperature-related words, and I saw the modified yo yak that Lao uses for the unnasalised 'y' consonant sound in the word เย็น 'cold'. (That letter has been borrowed into the Tham script as well.) Inconveniently, I don't read Chinese.

The second and third dictionaries look like the Tai Viet script to me - languages include Red Tai, White Tai and Black Tai. It seems too legible to be a Shan script, though I did wonder at first if they might be a precursor to the Tai Le script used by the Chinese Shan. This identification is fairly tentative - I don't read the Tai Viet script.

I must say it's quite confusing that the Tai scripts are written on their sides in these dictionaries!