The RCBS custom shop turned out my .256 Newton dies in about 3 or 4 weeks and I paid $65 plus shipping in 1977 dollars.. I resize and trim .270 Win brass, but 25-06 cases would maybe work a slight bit better because of neck thickness. My little hoard of original brass cases is more for amusement, since they were last manufactured in 1938. It takes about 5 minutes to adapt each .270 case to new dimensions. That extra time is one of the other drawbacks to obsolete cartridges. Also, IIRC, some African countries require that the imported ammunition and rifle must match, presumably talking about headstamps and engraved info, but I'm not knowledgeable about that.
Reloading data for the .358 NM is readily available and tested safe in modern guns with modern powders and other components, which I think is a plus when compared to rounds like the .333 OKH or .35 Newton. I agree with your Vintage Cartridge Nostalgia comment until I have to go out on thin ice with unknown pressures and obsolete powder comparisons.
I'll send a PM concerning the dies.
