Project migration that I lost access to new org account

[jhwa_dm]

Long story. My Google account was set up incorrectly with no organisation assigned. This account was then set up with admin access to a GCP project with no org but with billing account, which holds datasets from GA etc.

When IT eventually fixed my Google account to be connected with my organisation, I could no longer access the GCP project. I still have the project name, project ID, billing account name, and billing account ID.

My organisation has another GCP project that I have access to now, with basic support. No one seems to know who the internal Google Admin is. How do I get access back to the previous GCP project, and tie that back in with my organisation?