I think the Plymouth is a '58, 57 has little horizontal trims where the tail fin trim kicks up, which this does not have, also they had conical hubcaps and these look more like the '58 ones although the pic is pretty fuzzy. Also, '61 T-bird had a raised rib on the hood on either side of the hood scoop and '63 had scallops on the doors with 3 little trim ornaments on each side which makes me think the one pictured is a '62.
Took me a moment, but I get it now, as well as Stu's comments about the color. Thanks again, and thanks Squablow for the '62 detail.