Looks like the original owner had a custom top horn (not protruding more than the lower horn) or alternatively he/she or a later owner had it worked on to be reduced (note second strap button on rear). Very pretty nonetheless. Great ad though - no description and no price!
http://www.morenomeroni.com/project/alembic-distillate-1989/
I'm thinking it's a Small Standard body (Stanley Clarke). The strap button on the upper horn was probably also added by an owner.
I checked with the shop. Its 4.6kg and €4000 if anyone is interested. Too heavy and pricey for me