Nice build!! OK! So, how did they work & how did you make out? Getting bib's with the options "we" want are hard to find. Lucky you can sew.
If this were like an order, I would ask for 2-way full length leg zippers, elastic openings at the bottom, a way to tighten up at the waist and a means to inert foam knee pads. Maybe a higher back that goes to the base of the neck...... Just dreamin'. Lol BTW, down to what temp did you wear these baby's in?
They work great. Had them down to zero degrees (F) recently with a fleece thermal layer underneath and they were quite comfortable. Without an extra thermal layer, they're good down into the low 30s, I'd guess. The water-proofing on the nylon is better than I expected and I've sat through the rain without ever getting wet on the inside. Very happy with that. The thigh pockets are fantastic and easy to access and the thigh vents work great after/during a hike in to keep me from overheating but also not spending a lot of time at my hunting spot getting clothes back on. The waist pockets are good for my keys and hands and I use the chest pockets for wallet, pocket knife, etc. One thing I'm still not super happy with is the elastic on the shoulder straps. It's necessary to allow me to sit down in such a "fitted" suit but I think I need a little more strength in my elastic. They currently sag a bit when I'm not sitting and it's a little annoying.
I didn't need a way to tighten the waist since they're tailored to my body. There's enough room to be comfortable with my layers underneath but not really any extra space beyond my "typical" cold weather layers. In the attached picture, you can see that it's pretty snug against me. With a single layer, I have about 2 fingers width inside the bib at the waist and chest. (It's actually that way down the thighs as well and opens up at the knee.) With my hunting layers, it's less than a centimeter of extra space. Adding a way to tighten the waist would just be extra material and weight. I considered some belt loops to be able to wear a knife or side-arm belt but decided against. If I really want one, I can still wear it over without much concern.
The black patches on the knees are actually pockets for knee-pads, so that's already done.
I considered a high back but decided against it because I hike with a backpack and get plenty warm enough as it is. When sitting, I often have a tree at my back but didn't consider the extra benefit of a high back in a saddle. My DIY jacket (in another thread) satisfies that need, for the most part. It is a good suggestion, though, especially for saddle hunters.
Full length zippers on the legs would be a good option but I would recommend some baffles behind the zippers to keep drafts out. It may not be necessary, though, and doing without would give more venting options. I'd have to play with that a bit to make any final decisions.
I'm not sure the benefit of elastic ankles/cuffs if you have a full length, two-way leg zipper. Help me understand that one.