...yes, your can (nice can, by the way) is probably 10 years earlier than the one on ebay, I would guess 1920 or so...there was a book published a year or two ago, about Port Arthur, by Elton Gish...lots of product photos in it, from original negatives...no Texaco collector should be w/o it...I'm sure many cans from the same period as yours are in there...
Looking for better Gulf items: signs, globes, cans and paper - especially porcelain Gulf flanges, and Gulf A-38 & A-62 ad glass...