What is the process for obtaining an interim tourist visa after switching from a Non-Immigrant B Visa to a retirement or Non-Immigrant O Visa in Thailand?

Perhaps I am mistaken, but once you stop working I believe you have to leave the country within 7 days. Then you can apply for a new visa and return as a tourist.

We're confusing TWO very different things.

A visa exempt entry is when you enter the country without having bought a visa from a thai consulate before hand and are stamped in for a number of days for free. Most western countries get 30 day visa exempt entry stamps.

A tourist visa is something you BUY at a thai consulate in another country. They are sold in two ways only. A 90 day single entry tourist visa and a 6 month METV <- multi-entry tourist visa.

At most thai consulates in S/E Asia all you're going to get is a 90 day single entry tourist visa. What that means is the visa is valid for 90 days once you get it and you have that long to enter the country and get stamped in for 60 days.

You can also extend a 30 day visa exempt entry OR a 60 day tourist visa entry by 30 days at the immigration office for 1900baht

60 days + 30 day extension

I trying to remember. Manila, Ho Chi Minh City, Yangon, And I think there was at least one more. All SETV

I was in the same situation. So far I have gotten 3 or 4 tourist visas. My plan is for a couple more years.

I don't understand the question.. You can get as many tourist visas as you want to (or until a consulate red-stamps you and says you can't get any more from them).