I'm setting up a CTR with factory, non-adjustable stock now. I'll definitely need additional comb to get a solid cheek position; I've got a giraffe neck
I gave a lot of thought to Triad Tactical stock packs, making my own out of foam or whatever else, but ultimately decided if I was going to truly fit it to me, I'd need something adjustable and didn't like the look/idea of taping a bunch of material to the stock.
Ended up deciding on an adjustable riser from Matthew's Fabrication. It does require drilling 2x 1/4" (IIRC) holes to mount.
The original comb has a plug in the middle, remove that and there is a screw that attaches the comb to the stock.
I didn't want to drill my stock initially either, but, it's not like it's gorgeous wood, or hard to find, and I finally figured, if you really want to fit the gun to you, and not you to the gun, it's the most expedient and "correct way".
I'm a noob on precision rifle, so apply your chosen level of skepticism to the above.