Dave and Howard,
I'm not trying to rain on anyone's parade. It's just that I was burned on a couple of Clemente sigs early on, and I vowed never to let it happen again.
I remember the name of Clemente's "alleged" ghost-signer, it was Phil Dorsey. It's possible this item was signed in the late 1960's by Dorsey and then the test could have been produced. I don't have the knowledge on Topps test issues that the both of you do, my opinion was only on the auto.
Here are some more of mine to compare:
Here are some that are not mine, but I saved scans:
Note the differences in how Clemente formed the letter "T", also the "Best" in Best Wishes, the formation of "b" in Roberto, the legs in the "R" in Roberto,etc. I would not bet my life on it, but like I said I have seen A LOT of Clemente autos and although there are some variances in his legit signature, they still have the same characteristics.
Mike