I've come across an old set of golf clubs. I'd guess 20-30 years! They are Jack Nicklaus RPM Parabolic Groove MacGregor. Full set of irons. Can't seem to find much on them on google. I don't plan on using them as I have a set if my own. I was gonna sell them but no idea how much they are worth. There are none like them on eBay. Any golfers out there know much about them?