Treasure Island - Squire Trelawney Multi-Cache

Stage 1: At the above coords find the corner stone subtract year from the number 2206 this will give you the last three digits of the west coords.

Stage 2: At the above location find the No Dogs sign and using the first four digits from the "ord" number subtract them from 1126 this will give the last two digits of the north coords.
Once you have figured that out go get that cache.