The cache is not at the listed co-ordinates, but is 267 chains and 4 links from the other end.
That by itself should get you close enough to find the cache, but different tools give very slightly different results. For fine tuning let the year of his birth be ABCD and the year of his death be EFGH. The final 2 digits of the northings are (C)(D-C) and the final 2 digits of the westings are (F-C)(D-C).
This is a replacement for OK0243, on which the final location has seriously deteriorated since it was set. The puzzle uses the same method as that cache, but different numbers.