How to extend cargo management tab in the cockpit?

Dear experts,

We are trying to add the consignee description to the cargo management tab in the cockpit. We have identified the component as /SCMTMS/WDCC_BOOK_LOAD, but we have problems to find what is the structure that must be extended to add the new fields, as well as the method to fill these fields. Would there be a kind of procedure to find this information by ourselves? We have done this kind of thing in the past, but other developpers had created a new component and it was easy to just modify the same Objects (also described in note 1818803). But now we start from scratch...

Also, is it better to copy the component configuration and modify it directly (how to use it in the cockpit then?), or is OK with creating some customizing for the existing component?

Thanks for your input

Petra