This Flighter prototype has a satin stainless steel finish that is very different from the normal Flighter in appearance. I am told it has the same satin finish as found on the Cirrus 61 pens.
Upon careful examination, this BP is not the same size as the 75 BPs. Both the cap and barrel diameters are larger. My speculation is that this is a transition piece between the 61 and 75 models.
While this prototype is a BP, it is likely a matching FP exists.
