An odd Einstein signature, start to finish. The numbers look off. The underline. The absence of any lifts in "Einstein", the formation of the "A", among others. While any of these things can exist in a legit Einstein, the presence of all of these things that are "off" in one signature is troubling, along with the typical "found in the attic/estate sale/Uncle Lou's army foot locker" story that's used to explain a formerly unknown, rare and valuable piece springing into existence.
Though not an Einstein expert, I've seen enough of them to know this looks like from out of left field.
$863 was the result.