You can easily get a job teaching skiing. Walk into the ski school director's office now and start the talk. Level I cert is a give-away for someone like you. Switching from old school to current skiing will help you get to Level II. You'll have to do that, and you'll need some good coaches to work with you to let you know when you've got it. Since you looked at L3 mock exams, I presume you'll be going for Level III as your final goal. Go for it, but be ready to spend lots of money on clinics too. You don't have to lose the belly to start this whole thing. Look at lineup at your local bump.
I wish folks would quit saying LI is a "give-away". There's more to it than just being a good skier.
A serious seeker of LIII will never make it the "final goal."