Maximizing natural strength training

Since I started back into a routine of lifting again I went back to the core basics and now that I'm on the other side of 40 I wanted to make sure I'm being not only efficient but realistic in my goals. I should say I lifted regularly from age 18~25, stopped and packed on weight (i.e. got FAT) then after a couple yrs of that got back into it and had a regular lifting schedule of 5 days a week for 5yrs, then it tapered off again and I've been on a sporadic 6 months off/on.

I came across this article The WeighTrainer - Your Maximum Muscular Bodyweight and Measurements and comparing my info to what the predictor is, it's really damn close to my current measurements, however at my past peak training level my muscle bellies were a bit bigger then predicted. So it's obvious there is no one size fits all.

So being an engineer and scientist I took all my measurements and built a 3D puppet form in CAD and used that get a look at what angles and form I should have for each lift. It sounds strange but it really proved to be quite helpful, I made a couple minor adjustments to my form and was able to immediately add more weight to my lifts. I guess I could have gotten the same from a trainer but I've been spoiled with lifting at home for the last 15yrs.

Some of my measurements, the good and the bad..
height = 6'4"
wingspan = 76"
weight = 250lbs
Circumference measurements COLD
Neck = 18.5"
Shoulders = 56"
Chest = 50"
Waist = 42" Really need to drop back to 34~36".
Thigh = 24.5"
Calves = 17"
Biceps = 17.5"
Forearms = 13.5"

So my goal for now is to hit a 1klb 3-lift power-lift total again, (best was 1,010 lbs yrs ago) and then get to 1,500 lbs if possible. Currently at 892 lbs My weak point is the squat, that lift is lagging by ~120 lbs to the dead lift and bench press at the moment and figure it'll take ~6 months to crack 1k if I stay disciplined enough.