A man, a plan, a canoe, pasta, heros, rajahs, a
coloratura, maps, snipe, percale, macaroni, a gag, a banana bag, a
tan, a tag, a banana bag again (or a camel), a crepe, pins, Spam, a
rut, a Rolo, cash, a jar, sore hats, a peon, a canal –
Panama!
This
and this
will not help with the puzzle, but may discourage you from staging
a canoeing accident then disappearing abroad. 
Geochecker will allow you to verify your calculations. Don't
forget leading zeros.
The coordinates may be slightly out due to the nature of
these things, but you'll have no problem spotting the hiding place
and it should be no more than 10 metres away.
Original contents included various pin badges, a rabbit
balloon, a dog-bone clip, a pathtag, a Groundspeak Volunteer
geocoin (too rare to allow to travel: please note tracking number
and leave), a Portugal geocoin and a travel bug. And a FTF
prize!