the issue isnt whether it is F1.2, it is clearly f2 (as it would be), that is obviously a miss print or the guy doesnt know what he is looking at. the issue is whether it is one of the 125 geniune 1977 Retina IIIC made from the left over kodak parts, issued as gifts.
there are a number of tell tale signs that show the difference but are generally kept secret to dissuade people from making replica's , the last genuine one i remember hearing about sold for around $3000 at auction ...the fact that this one doesnt have a serial number is cause for suspicion, the story presented by the seller that this camera is miraculously one of only two Retina IIIC that left the factory before a serial number was given is _________, yeah