Hi,
one of my Trading Post transactions (its id: 1489725948) has item_id 69595; however https://api.guildwars2.com/v2/items/69595 says that there is not item with such id.
The same situation with: 69023 (transaction: 3355254320); 69445 (transaction: 3355006952) and 69430 (transaction: 3353027601).