missing fields Merged

Each time I try to use the API toolkit I find data fields are just not available - only a selected set are present Latest example is Sop_orders_delivery_address record, needing the fields: postal_name, telephone, fax, e_mail I'm trying to export delivery details to another system and can't provide all the data entered on the order Is there any good reason why ALL the fields can't be available. I appreciate it takes longer to get the data the more fields are present, but if the fields don't exist we can't write the systems