Seems like Rodents are the bain of 'bolters' lives at the moment! eek
Squirrels,rats,mice and possums! (O.K. I know possum's aren't rodents.)But hey!They're critters all the same.
I'm with TooMany on this one...you've got to kill off all the germs!
I used POR-15 inside my cab on the areas that wont be seen and I would imagine it would seal in any offending smells!
I you,however scrub the cab out well you should get rid of the smell.Try and vacuum as much of it out as possible (be inventive for the nooks and crannys!) Persvere you'll get there! thumbs_up Good Luck! OH! Mask and gloves are mandatory on this one! Jock.

1950 Chevy Advance Design 3100 in Scotland
In the Stovebolt Gallery
More pix on Flickr.
I've definately got this truck thing in my blood ... my DNA sequence has torque settings
"Of all the small nations of this earth,perhaps only the ancient Greeks surpass the Scots in their contribution to mankind" Winston Churchill.