The following is just food for thought, so take it for what you feel it's worth. Without seeing what you looked like before starting your diet, 82kg to 71kg is 24 lbs. Wondering if you might have dropped too much weight and lost some size along the way (I know I did for my first show. Ended up winning the weight class but could have been bigger and fuller)? When you started training for your contest, did you train any differently? How long of a diet, and what was a typical day's diet?

As for chest, try 3 workout in a row focusing on upper and middle chest, then 1workout for lower? You just posted your leg workout, so I'll suggest that perhaps you want to split quads and hams? If you always crush quads first, you're more than likely a little gassed before training hams? Below is a copy of my current workout. The exercises are just representative, and can be switched to suit you needs. Just a guideline/suggestion. Quads and hams are split so I can focus hard on each.

Your back looks good. Just keep training for width and thickness.

Sunday: Chest/Abs
Incline Bench Press 4×10-15
Incline Hammer Press 4×10-15
Dumbbell Fly’s 3×10
Decline Cable Fly’s 3×8-12
Dips 3×10

Monday: Back/Calves
Rear Lat Pulldown Wide Grip 4×10
Machine Rows 4×10
One Arm Dumbbell Rows 4×10-15
Incline Machine Pulldown’s 4×10-15
Low Back Bench Extensions 4×10

Tuesday: Shoulders/Traps /Abs
Rear Delt Machine 4×10-15
Seated Dumbbell Shoulder Press 4×8-15
Seated Lateral Side Raises 4×10-15
Upright Row 4×10-12
Dumbbell Shrugs 4×10-15

Wednesday: Rest
Recovery

Thursday: Quads/ Triceps /Calves (Note I can't squat because of a lower back fusion)
Incline Leg Press 4×15
Seated Leg Press 4×15
Leg Extensions 5×20
Single Leg Extension 3×20
Triceps Cable Extension’s 4×10
Seated French Press 4×10
Cable Kick-Backs 4×10
5. Seated Calf Raises 4×10
Standing Calf Raises 3×8-12

Friday: Hamstrings/ Biceps /Abs
Lying Leg Curls 4×15-20
Seated Leg Curls 4×8-15
Hamstring One Leg Curls 4×10-15
Dumbbell or Machine Curls 4×10-15
Preacher One Arm Dumbbell Curls 4×10-15
Hammer Curls 4×10-15
Wrist Curls 5×10-15

Saturday: Rest
Recovery

__________________
I'm a hard knock flier and a rainbow rider, a straight shootin' son of a gun...

DISCLAIMER: I reserve the right to be wrong on every statement I make....