FWIW, and IMHO, you don't need to go this route. I find myself highly sceptical of the valididy of either for anything. OTOH, the TCD one does look nice and official, and the United Nations seal on it could be useful in impressing semi-literate police. I also don't like sending that much detail to an unknown over the net, especially to Bangkok!
I have always just used the one obtainable in Canada from the CAA, for I think CDN$18.00. And I might add that it looks TOTALLY different from the TCD one. And yes I have had to produce it a couple of times, and it was accepted fine.
Re handing your valuable licence over to who knows, make several colour photocopies of your licence and laminate it nicely, that will work fine - and if they want to hold it until you pay a fine, no worries!
Personal experience says copies are ok, even in the USA (for a Canadian licence).
I would suggest checking out your local Automobile Association and see what they have. In Canada it's a 10 minute process at any local CAA branch.
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