Bill, it's definitely not a 701. That--thanks to some strange numbering by W&S--was the highest grade of the 700 series guns. 700 was the base model, 702 the next step up. (And the 720's, 728's etc were based on the 702.) Then 701 was the highest. Yours doesn't even have the basic engraving of a 700, let alone a 701. Nor does it have other features like drop points, that are found on the higher grade Scotts.
I think the clue to yours lies in the 2nd para of Lagopus' post above. They were later guns made for Orvis, but of a "plain quality". That certainly fits the photos you've posted. Because the book's serial number list ends in 1978-79 in the 146,000 range, it would make sense that yours was a later gun on which they simply continued the SN's.
