The Cornwall OPC site at
https://www.cornwall-opc-database.org lists a baptism on 26-May 1790 at Rame for Richd. PRIST, son of Richd. and Elizth. The source is Exeter BTs which are actually on line and you can check out the image at
https://www.familysearch.org/ark:/61903/3:1:3QSQ-G93K-K93N-1?i=50&cat=1833668 . To my eyes, the surname looks more like PRISH than PRIST.