The Great Western Railway opened Culham station on the Didcot – Oxford line on 12 June 1844. The original station building (no longer in railway use) is in the Tudor Revival architecture of Isambard Kingdom Brunel and is a Grade II listed building.
Assume N51° 39 and W001° 14.
To complete the northings, multiply together the 4 digits of the number stencilled on the brick bridge near GZ; add the maximum weight from the roadsign twice; add the alphabetical position of the 4th letter in the 2nd word from the pub sign; add the number of Vs in the trio of signs starting with a BR logo and ending "ONLY" .
For the westings, 1st digit is the number of letters in the 3rd word on the pub sign. 2nd digit is number of Gs in the 5 words on the pub sign. 3rd digit is the alphabetical position of the 1st letter of the 3rd word on the pub sign. Then add the total number of Fs and Gs on the trio of signs used for the northings. You are looking for a pot at ground level.