Do you have a Parts table? Then it can be simple.
It would also help to know from where this portal should be looking.
I simplified things a lot in this description of course.
Yes, i have a parts table, but no it wouldn't wouln't be useable here as the PartNr (in the parts table) are not the same as the Partnumbers in the Inventory-table (actually, latter include the batchnumber as well) ... at least not to my understanding.
The layout-table is the same 'inventory'-file, i would use a second instance of this file for the portal.
Does this help you any further?
De-duping a portal is not easy at all - so let me suggest two alternatives:
1. Produce a report from the InventoryMovements table, sub-summarized by PartNumber (with no body part).
2. Find a way to make a Part related to its inventory movements. Then show a portal to Parts, based on a relationship using the x operator (showing all parts). In the Parts table, let each part sum its related movements, and show this in the portal.