DAM sync, Pulling fields from project level, attatch to proofs

I currently have a scenerio set up, I add a proof (document) to a project task for approval, once approved the document is synced to an external Dam and transfers across. 

Before syncing, a custom form is attached (asset details) that contains the meta data that matches up with the Taxonomy in the DAM.

The issue is, this form has to be atatched to each document, sometimes upto 40 documents can be added for approval.

My plan is to add the asset details form to project details as a (proj) so once each asset is approved, it pulls the meta data from project level and attatches it to the document before sync.

The problem is the data isn't being pulled from project level and I'm a bit stuck. Can anyone help?