You are correct. Extension Retirement Visa 1900 + Multiple Reentry 3800.(this was Nov 2017...wrote the wrong year😂😂) Personaly I need the reentry because I go to Europe once a Year (+ want to travel around SEA.)
In Austria you can only get the visa at the thai embassy if you are resident there (they want proof of this) or austrian citizenship. I could not do it in Switzerland. When I was living in germany (I am swede) I could not do it in Austria, possible however also in Sweden..