I am Canadian (currently live in Canada) and I spent 7 months in Chiang Mai on a tourist visa (2014-2015) and 9 months in Bangkok on a tourist visa (2018).
I do have the passport from my time in Bangkok (2018) but not for my time in Chiang Mai (2014-2015).
According to the information on the web site link that I have pasted below, I need to provide all of my entry and exit stamps for going in and out of Thailand on my passport. I can only provide this for being there in 2018.
I have emailed them (the Thai police) and I hope to hear from them soon, but if anyone has any insight then please let me know.
Please note that I do at least have a picture of the old passport cover page (and of course passport number)
A big thanks to all of those on this forum who have always been so helpful. It made my time in Thailand much easier.
Web site link:
https://pcscenter.sbpolice.go.th/news/APPLICANTRESIDINGINABOARD_32.html