The Tool Tray concept was introduced for 1936MY SS-Jaguar, apart from the one-off SS1 Airline arrangement (which was moulded). Three variants for 1-1/2litre, slightly different for 2-1/2 litre and totally different for Tourers. These were all painted black, top side, underneath and bracketry.
For the 1937MY, still the same three variations, with slight changes only to the 1-1/2litre and 2-1/2 litre, Tourer staying unchanged.
For 1938MY a totally revised tool-tray design was introduced, but only the one variant - now common to both 1-1/2 and 2-1/2 litre cars, and these introduced BLACK flocking finish instead of the previous black paint.
IN all cases I use the MY (Model Year) terminology/demarcation as per Alan Crouch’s SS-Jaguar book, which gives exact dates and chassis number ranges.
And to date, available evidence of original/unrestored SS-Jaguar Tool Trays is consistent with these MY demarcations, as indeed as was the marketing/motor show release practice of SS Cars Ltd.
So until I get PROOF of anything at odds with above MY demarcations, I remain happy with these current conclusions, but always on the lookout for further examples of original/unrestored tool-kits/trays to reinforce, or indeed challenge these current conclusions.