I missed a few, but here are some of the quest IDs for leatherworking and engineering items and masters.

[Intact Coil Capacitor]
70275

[Wind-Blessed Hide]
70300

[Spare Djaradin Tools]
70280

[Well-Danced Drum]
70269

[Treated Hides]
70286

[Decayed Scales]
70294

Erden
70256

Frizz Buzzcrank
70252