If you know how to do this:
North coordinate: 39 Deg 18.(G731:R5:C8)
West Coordinate: 75 Deg 35.( G731:R7:C13)
Note Not availability on Sunday, Saturday after 12:30 pm or evenings after 5:30
This is a simple puzzle once you learn how to apply these sets of three numbers for the cache. (Grid:Row:Column) shown as Gxx:Ryy:Czz
Grid:
The Post Office will have multiple walls with post office boxes. A normal group of boxes is about 5 feet tall by 2+ feet wide and a wall may have from one group of boxes to many groups of boxes. The Grid refers to ALL of the groups of boxes on any particular wall. Each wall of boxes is considered a separate Grid and there is only one Grid per wall. (Exception, if a wall has a door or opening that separates a set of boxes from another set of boxes then each one of those different sets of boxes would be a separate Grid.)
The Grid number is determined by the number of the P.O. Box in the upper right-hand corner of the Grid.
Find the P.O. Box number that matches the Grid number and you are standing in front of the Grid you need to use.
A Grid has rows of boxes that run from left to right and columns that run from top to bottom. The P.O. Boxes at the bottom of the grid are usually bigger than the boxes at the top. The rows will normally lineup across the entire grid, but the columns will not. There will be more columns on the top of the Grid and less along the bottom of the Grid.
Row:
Starting at the upper left corner of the Grid and counting from top to bottom, the top Row is 1 the next Row down is 2 and continuing on to the bottom of the Grid.
Column:
Counting from left to right, the left most box is Column 1 and the next box from the left is Column 2 and continuing on to the right of the Grid. Warning, Row 1 will probably have more Columns than Row 9, so be sure to be counting across in the correct row (That is why the Row number is given before the Column number).
First step is to find Grid 731.
Now go find the correct P.O. boxes and final coords are:
North coordinate: 39 Deg 18.(G731:R5:C8)
West Coordinate: 75 Deg 35.( G731:R7:C13)
Math check: The sum of missing digits (last three) of North PO box is 11. The sum of missing digits (last three) of west PO Box is 15
The Smyrna Post Office Lobby is open M-F 5:30 am to 5:30 pm and Saturday from 5:30 am to 12:30 pm. It is closed Sunday.
The cache is NOT in or next to the building, but is about a mile drive away
Special thanks to Evanspack and tabbikat who helped with this cache