[uvaspina]

From the (very) little research I did, it appears that your auto is most similar to the ones he did in the early 50s. (If you do a google image search, you'll probably see what I mean). I noticed many slight variations among the autos I looked at. -For example, the squiggle under his name varies a good bit. The "T" sometimes has additional flair, and so forth. All and all, in my far-from-expert opinion, it still seems consistent with autos that have been authenticated.