Please kindly refer to below link.
This is a well known aquarium on our end which does imports in many oddballs. Interested parties can contact the owner for exports if interested as well.
Im in no direct relation to them, just a regular customer of them.
http://i1035.photobucket.com/albums/a435/stonesaquarium/181213/20131219_011958_zps0d4ec434.jpg
Look at the length in comparison to body height for TS's tiger. You don't see this contrast in ATs. Unless it is also a short body AT. In terms of colour, like I said, for those of you who owns a yellow coloured AT, do try the following :
Put the AT in a white based tank. With proper lighting and diet. The so called yellow based AT will turn silver. I have kept many so called RARE YELLOW BASED AT. NONE have ever maintained its yellow colour after being put into a white tank and a change of diet.
Diet involving lots of carrotine intake plays a big part in the colouration. Its the exact same logic of people having Oranged Based ITs. Do the same thing and you will see the orange fading to a yellow colouration.
To answer robroy's question on rarity, why not compare it to the even rarer Chao Pharaya River ST? Please do view below link for an extremely rare ST with the most ideal features; rat face, semi-short body, Thick knife-like curved bars, ST tail; etc.
http://i59.tinypic.com/5nkink.jpg
My point to you, robroy, is that no matter how rare a specimen can get, with proper connections and luck, it is still possible to get such a piece.
In this case, the previous owner of this rare NGT may have got it from a lucky source.