The Game is Afoot Multi-Cache

This is a two-stage puzzle multi-cache. The puzzle is rather difficult, so this cache may take a couple of trips: one to find stage 1 containing the puzzle and one to find stage 2 once you've solved the puzzle.

I would recommend parking at Douglas Walker Park if it's open; otherwise you can park at Winchester Cemetery. Once you find stage 1, you'll be presented with a puzzle that you'll need a "master mind" to solve. The solution consists of four numbers, ABCD. Starting with the stage 1 coordiates, add AB to the last three digits of the north coordinate and add CD to the last three digits of the west coordinate to get the location of stage 2.