Lucky break ..... but detail is quite hard to come by for the Panther. As I understand it, the first (1954 400d for diesel) version had the RUMI engine and a 'plastic' body by Colli. By 1957 and under new ownership the 400b (for benzina-petrol) version had a smaller engine and a larger body by Zagato. This second version had the wheel discs seen on the pictured car so I deduce that it was a 400b proposal - but by whom? I have never seen this car before and can find no reference to it. Period advertising mentions a Pantherbus, but that also yields no google response.
My shortlist, based only on style, is Monviso, Monterosa, Scioneri or Viotti. I hope this was a Viotti proposal for ISCA, who took over the Panther development.
