I know this thread is 4 year old, but I recently came into a Kimber Hunter and it was followed closely by an aftermarket stock (MPI) with blind magazine . As per the OP, the Kimber parts are non-existent in Canada at the moment; as such, I was reading every post I could on alternatives to Kimber parts that would work with the new stock and 84M action. I tried a short action Ruger M77 MkII mag box but it was wider than the mag well opening (intended for a factory Kimber mag box). In the end, I took a chance on a Remington 700 SA BDL magazine box follower (these are kind of nice relative to the factory magazine or other modern plastic units). The magazine box was not a perfect fit but it was quite close, so after some very light filing at the rear split in the box to reduce the rear width and top edge (narrowing the thickness of the magazine box from the outside so as not change feed lips) and some plastic shims (mag well shaped pieces of yogurt container lids) in the bottom of the mag well to raise the height of the box, the gun feeds fairly well (and doesn't seem to be binding)...or a least a lot better than it did from the brand new factory magazine. An ADL magazine box might have worked better because I gather they are taller but the BDL worked fine with shims and it still holds the max capacity of the mag well (3 down). One note though, you have to be extremely careful to align the box/spring correctly when assembling the parts (I like putting the mag box in the action and putting action and mag box over the spring (in the well) to achieve correct alignment. I probably took apart and reassembled the gun 50 time to get everything working, but it was all a good learning experience. Now to test if there were any impacts to accuracy from my fiddling.
As an aside, I want to try to make a short range peep sight gun out of it and in my sight option research I determined that, although very nice, the NECG banded front ramps would require a bit more metal work to make it fit than I was interested in. Revelation - a Lee Enfield No.1 MKIII banded front site is a pretty well perfect fit for the 0.56" muzzle diameter of the Kimber Hunter.