77 kz1000 bought with early forks on it 73,74,75 ?

My bike is a 77 kz1000 purchased 3 years ago. It has forks on it that belong on 73-75 z1's. I know that from looking at so many pics on the net,but is there a way to tell if they are 73,74,75? I want to sell them and list correct info. I just watched a set of nice 74 z1 forks sell for $406.00 on ebay today. Mine are just about as nice,and should bring some money.

Yes, the z1 forks have a orange reflector built into the fork, it is unique to the z1 and also the z2 750 the z1's baby brother. Here is a pic of my 74 Z1 900, right after i got her running.