I also reload for my 7wsm hunting rifle and I have learned alot in doing so. First, as you have noted, brass can be difficult to find. When I first started out with this rifle, I had one bag of prepped brass and one bag of fired brass. I didn't keep track of how many times cases were fired, resulting in situations where a bag could have brass fired twice or five times. This led me to accuracy problems and random split necks, not to mention lots of frustration.
Here's what I do now. I buy new brass, then sort by weight. I record the weight of every case to 0.1grain accuracy. I'm not sure why you went through the effort of weighing all your brass and then lumped them into groups (hopefully you just reported it that way for your post, not actually sorted that way). If they are lumped, you might want to re-weigh as above. It's only 100 pieces.
Next, I look at the ammo boxes I plan to use. For WSM you basically have two choices. 50 rounds or 22 rounds. I prefer the 22 round boxes, as this is a hunting rifle and I don't need to carry 50 rounds for hunting. Once brass goes into an ammo box, it stays with that set of 22 pieces for the entire life of the brass. I mark them with a letter (box A, B, C, etc). I prep them the same, load them, fire and then repeat, as a single set, never mixing between boxes.
If using 22 round boxes like me, then you're looking at 4 boxes (88 rounds) and maybe a 5th box with up to 12 rounds. I would play with the numbers a little and see if I could get each group of 22 pieces within 2 grains or less. Most likely you can get 4 boxes at 2 grain increments, since the entire group is just under 8 grains. Within 1 grain would be even better, but you may only get one box that tight. This will tell you what brass to cull.
Personally I have winchester and CCI magnum rifle primers, so I start out with winchester for the first few firings, then switch to CCI once the winchesters seat with little to no resistance. Also, I anneal after about four firings to prevent split necks. If you stay off the max, you should get LOTS and LOTS of firings from this brass (winchester I assume). Lastly, expect about 700-800 rounds from that pac-nor barrel (that's how long mine lasted). After that, I highly recommend a cut-rifled barrel (I like Brux).