Hi
Googling "gamrie st john" without the quotes comes up with a number of interesting links regarding this churchyard and church - and the surrounding area.
Haven't been able to find an address as yet for St John's although Gamrie ceased to be a parish in 1975 with the boundary re-allocations, for Turriff I've come up with St Ninian's, Gladstone Terrace, Turriff, Aberdeenshire, AB53 4AT - 01888 560282.
Hope that helps