I moved from one Immigration District to another, while I was in the process of obtaining my Retirement Visa. (I moved from Bangkok to Pattaya.) Do I need to return to Bangkok to get my Re-entry Permit before leaving the country ?

I have just noticed the posting on here about Re-entry Permits now being available at the Departure area of Suwanaphum, but I prefer not taking a chance that they will be ready, willing and able to do it at that point.

Try getting it at "Pattaya", but take proof with you of your new address to show that you now need to apply there instead of Bangkok.

Also bring your ticket with you, some immigration offices want to see it.

If you have started doing 90 day reports in Pattaya expect they will issue and nothing lost is asking. If not would plan trip to Bangkok or early check-in for flight. As long as you have the required documents do not believe getting at the airport will involve much extra wait. But, as you, have always been of the do it early and not have to worry persuasion.