Behind looks better than the front. Back looks good, lots of potential.
As a bodyweight only enthusiast, so are my recommendations. I'm sure a week of high volume push-up sessions, mixing up the types of push-ups (some with hands on chairs and going very low), would carve some nice lines into your chest. If you are up to it, how about 20 sets of 10 reps each to start with 60 seconds recovery between each set. Or if you are capable of more, how about 25 reps every 15 minutes until your total count is 500.
Then take a photo, but be prepared for some next day healthy
muscle soreness.
Whatever you do, you seem to be a man on a mission so I'm sure your photos in 3 months from now will show some real nice progress.