Tier 4 merchants from the official guide:

The Scribe - Random Encounter - Armor seller

Doc Anderson - Random Encounter - Medic

Ann Hargraves - Found at the WRVR radio station - Clothing

Ron Staples - Random Encounter - Restaurant

Vault-Tec Rep - Goodneighbor - General store

Rylee - Random Encouter - General store

Holt Combes - Vault 81 - General store

Smiling Larry - Random Encouter - Weapons

Are all tier 4 merchants

In adition to those there are also:

Shefild-bum from Diamond city

Tina de Luca- from vault 81(bugged atm wont actualy leave the Vault despite you persuading her to join you)

So what i wud like to know has anyone menaged to find any others, and if yes do plz post who and where:)