Catch and Release

[Turtle]

Dads tackle box --- Should be Dad's instead of Dads, which is plural in meaning.
was a metal first aid kit
from the second world war.

Its bumps reminded me
of my grandfathers skin;
coarse and uneven, but warm and familiar. ---I like that you don't have a break here, but you could experiment with breaking after the comma to give more of an effect to the line "but warm and familiar."

He was a medic 
in the North African campaign 
before getting shipped back to Canada 
with a bullet in his leg. --- Although not a direct rhyme, the combination of campaign/Canada/leg has a rhyming effect to my mind's ear when I read it. I really like this stanza.

His limp brought a humble grace to his gait, 
and his face bore the smile of a condemned man 
set free.

I really enjoyed this poem. It's simple, and conjured some very epic imagery with very few words. The ending was well done too. Having a line break right after man was a good choice. It gives a lot of emphasis to the line "set free", which completes the metaphor in the title very well.