If that's the case, and no (in this case) left handed stocks are available, and you feel that you could cut a slot for the bolt handle, why not have a stock inletted "without" the bolt handle cut. Right hand stock available that fits the same action profile and you just cut the slot on the left side? Hack saw, sandpaper and a brush with a little finish for the bare wood.
I'am not thinking a full refinish job, just at the bolt handle cut. And if you don't think you could acomplish that part of it, then you would have to wait till one came available. That's the down side!
And myself, I would consider cutting a bolt handle slot a "small adjustment".