I would agree that this looks like a Palmer Second Catalog Model D - it was most probably made in the mid to late 60s/early 70s. The second catalog Palmers had longer butt caps than the first catalog Palmers- and the ferrules were mostly permanently attached and did not screw off to be changed. A rubber bumper was easily added to most second catalog Palmers. The ferrules were mostly NOT Ivory or Micarta ( they did yellow with age), but they were mostly a synthetic plastic polymer material. The joint screws were 99% 5/16 18 but , yes you may see a 5/16 14 joint screw, but rare. Palmer did not use as many Titilist cues in making the second and third catalog cues- This looks like a Titilist- but Gus Szamboti, Burton Spain, and others supplied 4 veneer pointed forearms to many, many of the second Catalog Palmers.
The cue should play as well as any "modern" cue- it depends upon the shooter. they were very, very solid playing cues. The shaft, if reasonably straight, should probably have a new ferrule, tip and reconditioning if you intend some serious play with this cue. Leaving the cue as is --- always an option for originality- but the shaft looks like it needs some front end work to be playable.
Nice cue- if reasonably straight, does not look banged up on the butt end- probably a current market of $600 to $1000 as is- depending on who is looking to add to a vintage Palmer collection.
I'll add- if it was my Grandfather's cue- it would NOT be sold.