Tinkering Supplies Vendors
This page contains a list of merchants that sell an assortment of Tinkering Supplies. There is an NPC on this list for every single race's home town as well as some of the more commonly visited zones, like Plane of Knowledge.
The majority of Tinkering Items are sold by all of these merchants... however not every item you need for Tinkering is sold by every merchant. I recommend checking the Plane of Knowledge and East Freeport merchants first if you're after something uncommon.
Most Convenient NPC List
This list not only demonstrates the easiest of these NPCs to find but also the NPCs that sell the most stuff.
#1: Tabben Bromal in Plane of Knowledge
#2: Engineer Beri in Plane of Knowledge
#3: Rylin Coil in Ak'Anon
#4: Ethrrian Drowius or Eyunon Storius in East Freeport
Tabben Bromal - Plane of Knowledge (Tinkering Supplies)
Tabben Bromal is found just southeast of the small bank in Plane of Knowledge. Aside from Tabben there's another NPC you can also visit, Engineer Berri. She is also located in Plane of Knowledge and sells most Tinkering Supplies.
Rylin Coil - Ak'Anon (Tinkering Supplies)
This merchant is missing some of the items that the PoK and East Freeport Merchants carry. Silk Lined Steel Helm, an ingredient used in creating Rebreathers is one of the items that comes to mind.
Ethrrian Drowius & Eyunon Storius - East Freeport (Tinkering Supplies)
These NPCs are not on find. They're luckily pretty easy to find though considering they're smack dab in the center of town.