Notes

CHAPTER 1:
Tennessee Walker with exclusive Mahogany Bay coat - Starter horse after first misssion
Oil company letter to Cornwall ("Who the Hell is Leviticus Cornwall" looted in the last wagon)
Mining company letter to Cornwall ("Who the Hell is Leviticus Cornwall" looted in the last wagon)

CHAPTER 2:
Jimmy's Pen ("Polite Society, Valentine Style", only if you spare him)
Shire with exclusive Raven Black coat (Given to you in "Exit, Pursued By A Bruised Ego", stable it instead of selling it during the mission)
Liberty Hat ("An American Pastoral Scene" and stranger's mission "A Fine Night For it" during the second wave, may take a retries before it spawns)
Newsboy Flat Cap ("The Sheep and the Goats", worn by Cornwall's men)
Antique Watch ("Money Lending and Other Sins II" open the drawer with the watch, take other things until debt is paid, run away to the point where Wrobel despawnes, then come back and get it)
Jack's Drawing (Thimble request from Jack in chapter II)
Rare Shotgun (Hermit’s shack, available from chapter II)
Bucket Hat (Worker at Lumberyard near Strawberry BEFORE it gets deserted, best during chapter II)
Fundraiser (between II & VI)
Scout Jacket [unique color] (Pearson's rabbit request reward, between II&IV)
Vaquero Rider Spurs (Dutch's pipe request reward, between II&IV)
Ravens Claw Talisman - Get into Sinclair's cabin immediately after "Geology for Beginners II" and get the Old Brass Compass (an item used to craft it)

CHAPTER 3:
Rare Rolling Block Rifle ("Magicians for Sport")
Golden Shield ("Blood Fueds, Ancient and Modern" inside the manor on the fireplace)
Braithwaite Brooch (Catherine Braithwaite's corpse after "Blood Fueds, Ancient and Modern")
Penelope's Bracelet (Accept as reward after "The Course of True Love", not accepting won't let you have it in your inventory)

CHAPTER 4:
Lion's Paw Trinket ("He's British, of Course IV" - collect the trophy (paw) once you kill the lion)
Electric Chair Blueprint (Loot professor Bell's corpse after "The Mercies of Knowledge - VIII", available from Chapter IV)

CHAPTER 5:
Sun Hat (Best during "Savagely Unleashed", might take retries)
Scarlet Macaw (Guarma animal)
Blue and Yellow Macaw (Guarma animal)
Great Green Macaw (Guarma animal)
Red-Footed Booby (Guarma animal)
Red-Tailed Boa Snake (Guarma animal)
Rainbow Boa Snake (Guarma animal)
Sunglow Boa Snake (Guarma animal)
Green Turtle (Guarma animal) - can't be skinned, Arthur draws in his journal if studied.

CHAPTER 6:
Owl Feather Trinket ("Archeology for Beginners" - do not kill anyone at the camp)
The Widow of Willard's Rest II&III (complete I before epilogue, available from chapter VI)

EPILOGUE 1:
Worn Flat Cap [unique color] (John spawns with that hat, drop it and pick it up for it to be saved)
John's Gambler Hat (John spawns with that hat, drop it and pick it up for it to be saved)
Thoroughbred with exclusive Seal Brown coat (Rachel) - John's starter horse
Ancient Viking Comb (At the old Viking tomb in Roanoke Valley)
Giant Boar Tusk (Take the trophy from the giant boar after "The Vetaran - IV")
Native American Ring (A random event available any time, but the ring is lost forever if the Veteran's corpse isn't looted)

Epilogue 2:


Always:
Ornate Dagger (when you're done with "The Vampire of Saint Denis", it can be missed if you don't pick it up)
Fisherman's Hat (Legendary fish mission strand, at the final mission when he gets pulled into the water and leaves the hat)
Carolina Parakeet (Study, kill and pick one up before killing 25 of them, afterwards they're completely gone)