Sorry to read that about your lungs, thats a scary thing no matter what the cause is. Whatever you do, take care of your self, Breathing is kinda important for most things.
I like your Leather and I'd bet the Suspension, Electronics, Hydraulics work was fun and a blast when you got to see your work in actions. Leathers a good choice imo for you because of being able to be creative, spend the time on the detail and knowing your work is appreciated.
I think that is probably what draws many of us to it....