help in id a caliper

I have what i believe is a 1972 z1 front forks i purchased it about 25 yrs ago and was told it was off 900 kaw never was told what year it was i am now trying to find out it has the code 7 d 2 on the front rotor and all the pictures i find are for 73 and up and have a different style caliper then i have the lower fork tubes look right here are some pictures