1. In the year 1985, registration of property through registered GPA was perfectly valid,
2. You shall have to confirm whether the Survey no. has been changed by the authority or there was a mistake committed by mentioning survey no. 80/1 in place of 80 while registering the GPA,
3. If there was a mistake committed while registering the GPA, register a rectification deed,
4. In case the registrar refuses to entertain the said rectification deed, file an application before the court praying for declaration that inadvertently 80/1 has been mentioned in the said GPA and all other subsequent records as survey number which is actually 80, and also a direction upon the registrar to rectify the istake in registration dosuments accordingly.