I am not sure with this one. I cant see enough but what I see makes me unsure of authenticity. I would lie to see clearer markings inside. Is it an auction? If so please post a link. Also wait for further opinion.
Looks authentic. The zipper pulls are correct, embossed with 't's. The zipper is metal, the hardware on the strap is embossed with TODS in the correct font and the circular stamp on the front looks good too. The inside tag is the tag used in the older TODS bags, this bag is from the nineties, and the canvas lining is correct. It was a heavier stiffer canvas used in the earlier bags.
Post pictures if you buy it in the TODS lover thread. It's good to have detailed pictures of all different styles of different ages as reference for others to use as a guide.