Barclay,
I'm glad you saw my post for what it was, and that your thoughts mirrored my own. Mr. Chamberpot fancies himself a "researcher", but, the truth is we already have a far better one here who posts under that name. Besides, he is still smarting to this day from having to accept that there were two companies that produced sliding breech guns with the name "Darne" on them-I straightened him out on that very issue years ago, and pointed out that he would really need to be able to read, write and speak French in order to decipher French gun catalogs, (he doesn't) and while he would like to forget it, it is unlikely that he ever will.
I suppose he thinks folks have forgotten that, but, my email suggests otherwise.
I suspect, but can't prove for you, that Kutter may have it right. My Father comissioned a Remington 700 in 7mm magnum in the very early 1960s, and the engraving is far different from that which has been applied to your gun. Proves little, I know, but there were some pretty good engravers working in Japan in that era.
I'll see about posting photos of the Remington.

Best,
Ted