I really thought there were a few countries that had forced the airlines to allow TAs and OTAs to issue the tickets in their country and ignore the "sell only in country x" clause. I thought someone had figured this out for some of the ex-CMB fares that I had been booking and was getting them issued in Canada.
I found this place
Snowbirds Travel & Tours in Yangon that seems to do international air ticketing. They might be able to give a quote and set a reservation up that you could pay for on arrival.