I found a Remington 760 pump on Gunbroker in .358 Winchester. Trouble is Remington never chambered a 760 in .358 Winchester.
I'm not breathless about the price, nor am I breathless about the way they ground metal off the barrel to re stamp it .358 Winchester.
I have no idea who did the work, but a gunsmith and a phone number is listed for questions.
Link:
358 Win 760 pumpPicture from link of stamp