Hey Mike! Oh nice, actually that 140mm width helps a lot in this case and the 125mm would do much better than the 75mm width skins.
Keep in mind that I'm assuming a lot here, but based on my experience and weighing that against what I'm seeing in that picture is that the reason you're slipping while climbing anything steep is because of the lack of skin width. If your knee and ankle aren't totally vertical over the ski (to be fair it's not really user error as that's a pretty tough feat to accomplish) and weighting the majority of that skin patch down against the snow, your weight is pressing into the edges which lifts the skin material off the snow and reduces the usable contact patch pretty quickly, hence the slippage. If your knee and ankle aren't perfectly vertical over the skin material then you're basically just edging straight down the fall line which as you've found isn't a super grippy way to go uphill.
I think that some full width skins would help a lot, but length also helps a ton. Getting a full coverage skin that runs the entire length of the ski but more importantly the entire width of the ski would be a lifesaver. It sounds like the pre-installed skins are great for flats, so you could just throw the new skins on for steep climbs. For that 140mm width though I don't have any material off the roll, though I do have some kits available in that width.
Nylon is cool, but a bit overkill unless you're planning on an Antarctic adventure or something in REALLY frigid temps. The Glidelite is my favorite in this case, especially because we actually have the kits available and ready to go. Find the STS Kit 140mm here
. The kits have a stripe of tape running down the center of the glue to counteract the insanely sticky glue but in this case that stripe will probably work more in favor of preserving your existing skin material than anything.