That's a lovely Plesioteuthis, Michael. Do you happen to know what is the diagnostic feature of the Plesioteuthids? I'm pretty sure it is the long tapering gladius but have been unable to confirm this. I'm particularly curious as I have a specimen of this species though it is not as nice as the one you have shown us, sans arms, alas.
It's a pity that there is practically nothing available outside the world of academia available on prehistoric coleoids; believe me I've tried for this site but the information just isn't there.
According to the literature I have on Solnhofen, there are at least 8 known genus of this animal, and some have more than 1 species. As well, there are a few unnamed/undescribed animals. Plesioteuthis has a long narrow gladius which culminates into a cone- the fins are attached at the sides of this cone. Trachyteuthis is also fairly common cuttlefish. It has a heavy, massive ossa sepia which can reach lengths of up to 75cm, and becomes wing like and widened at its posterior end.