Many thanks for any advice!
Can't find 24mm wide NATO strap that is thin enough to fit between the watch and the spring bar. Anything thicker than about 1.2mm won't fit. Have only been able to find 22mm wide NATO strap and it doesn't fit properly with a gap on either side showing silver spring bar. Bought 3 straps so far and I am not happy with the fit of any of them. Be careful with thicker fabric NATO straps as they are stronger than the spring bars Sony supply and will bend/break them is forced.
Its the only thing I am really disappointed about with the SW2. Sony should have left a bigger gap between the watch body and the spring bars OR actually made the fabric straps they advertise on their website available to us mere mortals.