David I am just refering to terms used. That he will be extending a NON immigrant O for a year based on retirement. He can't have his O visa "extended (within Thailand) to an ‘OA’ retirement upon your 50th". OA can only be obtained outside of Thailand.
David an OA visa can only be applied for in your home country. You also need the money in an account in your home country. As he is not 50, he is not eligible for this. So as you mentioned he needs a NON imm O before 50 which can be extended for a year (not to an OA) based on retirement where the money is in a Thai account or income statement.
Using Most passports, a 60 day tourist visa and also a 30 day visa exemption stamp can be extended 30 days. Some Nationalities get less, ie India on any visas.
People.always laugh at me.....But I say on many facebook pages....DON'T go to Female Officers...I stopped going to ANY Female Officers about 2 years ago and have bever had any problems since. Every story with a visa complaint says I was questioned by the IO......SHE.....asked me this, SHE got upset, SHE called her Manager....etc etc......always SHE...I am not being Sexist....it is a fact....!!!.....Avoid Avoid....!! Even if the line is double the size go to a man....!!!