Tables as options in Pivot Table not showing lookup queries

Tables as options in Pivot Table not showing lookup queries

I creates 3 query tables (Sales, Items, Customers) and setup lookup fields as follows
  1. Sales.CustCode > Customers.Custcode
  2. Sales.ItemCode > Items.ItemCode
The model diagram below demonstrates the relationships 

I amm trying to create a pivot table from the Sales query.  The Customers and Items tables are not showing as options.  Instead other tables that I dont need in the pivot are showing up as per pic

How do I
  1. Add the "Items" and "Customers" tables to the pivot table
  2. Remove the non required tables from the pivot table options