Notes from author
I tested my other one and changed it to this. Much better, by which I mean almost potentially viable. You'll need to do a lot of dodging because you can't take much of a beating.
Hollow warrior armor + Brigand trousers is the most convincing Indy getup by far. Not the most useful, but that's not what this is for. I've seen Indys with Leather or Wanderer armor, but this is much better. If you absolutely must, you can use the Wanderer, Shadow, or Black Leather torso armor instead. This lets you use the FAP ring instead of Havel's. Significant bonus, but you lose Indy points.
Stockpile cracked red eye orbs but join the Darkmoon covenant, so you can invade up or down. Invade in the Temple of Doom (Sen's) and the Catacombs for Indy-themed adventure.
Consider swapping the wolf ring if you want something else. Just stay out of range.
I keep a lightning crossbow and a chaos falchion on hand. Consider swapping the plank shield for the crossbow and putting a dagger in the right hand for ripostes.
Allowed weapons:
Falchion (machete)
Light crossbow (pistol)
Whip
Dagger (knife)
Plank shield (makeshift shield)
Skull lantern
Throwables (minus dung. Indy doesn't throw poo)
Pyro flame (for support pyromancy)
That's it. Have fun. It's a real challenge, but so satisfying when you pull it off.