Cool beans Ralph...
I have a Sheriff friend who has three bomb dogs, they're amazing. I went with him a couple years back when he had his eldest dog re certified, they had an empty movie theater set up for the exam and had planted a "device" somewhere in the theater, the dog goes in and sits near some seats in the back of the room in theater 2....The tester says "he failed"....My buddy says "bullshit, it's there"...The tester consults with the other certifier on what it means, it just so happened that the other tester had stashed another "device" on the other side of the wall where the dog was still sitting (in theater 1), and yes, that one was larger than the one in theater 1.

Needless to say, he passed. He has been training sniffer dogs for 30 years, maybe he can give you some pointers...

I love Labs, they're awesome, my buds "sniffers" are 100# German Sheppard's, but you get the idea...
Good luck with the new addition, you can't miss.

Take care and scream "HI!" to everyone for me...
GT