The given coordinates are for the Car Park just off the Chatteris High Street and not for the cache itself.
The cache coorcinates are:
033037412507475451380754086682034082342903304837810751537462009945195601927514170006124836
074754508100992476230140156240000648206600994321370751523224055215571307221275450758228775
You can check your answers for this puzzle on Mr_Crow GZ Checker
Cache is a magnetised vial suitably located!
Extra hints available on request!