BobinNH et al are correct. Those of us who care about such things are becoming fewer each day. I only have three pre 64s, so I do not consider myself a collector. I have several older Brownings. about fifteen years ago,I took a '63 copy of a Superposed Pigeon Grade twenty to the shop for a new pin. The dealer offered me $6500 to leave it with him. No way! However, today I doubt that it would fetch 4K. A couple of years ago, I bought a minty hand engraved BAR Gd III on GB for a little over $1300. I thought the gun would go for 18-19 perhaps and had submitted an automatic bid capped at 15. GdII s were selling around 11-12.
The new crop of shooter seems to be mostly into plastic, laminate, stainless or flat finished stuff. If you can't pick it up at Academy, Wally World, or Dicks for a song, forget about it.
Luck in disposing of your friend's books. I dispersed an estate for a family member a while back. I was literally years getting the right money for a high grade rifle, but it finally happened.
jack