myself i have not had much luck finding a replacement that would allow me to use the existing stock .
now that being said toW does carry some that have vering degrees of Concave . but they are all cresant .
flat early plates normaly carry a wider comb area .
note also that they are caste and will break if you bend them to much .
heating will help but again the will break as there is often inclusions within the castings .
Now what might help you is if your very lucky the inside , very back heal section of the butt plat may not have been milled . Possibly milled only a little . This will let you take quite a bit of that area . Thus flattening the butt even more by taking some off the heal combined with light bending.
You will just have to look . Its one of those cases of some are , some aren’t .
Also remember that A&H , JUKAR , CVA and NA all produced rifles that were very close to each other in shape and in parts
My advise as to bending of these companies brass parts is, that you better have a replacement either on hand or available