The place on Sukumvit sounds about right it had a car park taxi stand along side with the Woks out on the edge of the footpath.

The Tum Nak Thai was out a bit past an industrial area with a lot of what looked like used car yards, Robinsons Dept store was not far away, I remember seeing the building when looking toward the shoreline from where we we seated out on the jetty, seemed like it was a couple of blocks away.

Perhaps this is it ,TUM NAK THAI 131 Ratchadaphisek Road, Tel: 274-6420 or maybe an old listing or relocation, I've absolutely no idea of finding my way around, Need a map and a compass