If you select a shape, you can go to the Object menu, and then choose offset path, then choose the amount and it will create a separate path offset the specified amount. The original will remain so you have to delete it or merge the shapes to create only one.
Sounds easy enough, but I’ve had mixed results. I made a heart shaped puzzled and did that. The lines did weird things. Ultimately I offset in autocad and imported it back into Illustrator.
lovely piece of marquetry the arrangement of the grain of the inlay is great and really adds to the overall look of the humming bird.
Did you add any finish to it that can often make it look even better.
Great work 
Wow! I am darned proud for you too! Dang, the hummer and fish look awesome!