The 375H&H connot be re-chambered for any of the rounds you've listed because they are all shorter than the original H&H.. The only rounds other than wildcats it could be rechambered to would be the .375 WBY or the .378WBY.. As I see it you have three options, 1. Don't buy it, 2.Buy it and rebarrel it. 3. Buy it and resell it as is, as long as your not fooling yourself about how "good" the price is..