Value according to my 2000 edition of "Old Rifle Scopes
” by Nick Stroebel, the value is listed at a retail of $225 to $325, but that was very high retail even back then. They were made from 1958-1974. You would be very lucky to get $150.00 for it now, and even then it would only be worth that much to a collector. They are not really even collectible. A $150.00 scope today will be much superior in almost every way, especially tracking, field of view, and resolution and brightness because of modern advances in glass and coatings. Those old Imperials didn't even have a centered reticle. Completely superior today in every way. I remember selling some used ones of various magnification levels, but the only one I ever really wanted was a Premier 4x because it came in mounted on a nice old Italian Weatherby MK XXII. But back then, though, your dad bought one of the highest quality guns and riflescopes
that were available. Roy Weatherby was a genius, and I shoot his cartridges and guns today and love them. A amazing and delicious read is, "Weatherby: The Man, the Gun, the Legend" by Tom Grisham. Your dad was probably a classy guy who appreciated the latest technology, and had money to spend on getting the most modern shooting iron available at that time. Hope you use it sometime! Get a padded sling, they were kind of heavy guns.