Just curious, is Huynh Hoan Tailor still around? They would be located at 13 Phan-Van-Dat in Saigon. At least, that's where they once were. My father claims they were the best tailors back in the day.
There's still a Phan Van Dat street downtown, in District 1 near the river. Not sure if it is the same street as the Phan Van Dat street that was here in the old days, but it probably is. If so, then the tailor is probably no longer there, one side of Phan Van Dat street has been demolished for a new skyscraper, and the other side is a few banks, and a bar or two.