Hate to be the bearer of bad news but the body of what you have is not a 71. A couple of key indicators. 1) Battery in the trunk not in the engine compartment. 2) Raised hump on the floor of the passenger compartment for a catalytic converter, Mounting holes front and rear for tube type bumpers with shocks and 4) The front valence should be solid (without a lower grill) Look at the vin number on the cross frame of the firewall. If its a 71 it should start with either AC or BC

Hello,
Yes you're right. I investigated that and the car is a CS1 from 1975.
The title of this car was lost and the age that was written in the registration certificate was 1971, maybe a mistake when the car came to spain in 90's. I don't know.
Then when I bought it I asked for the car history and also a copy of the old title that was lost. There I saw that it was from 1975.