sul-dlss/earthworks#310 will add the reverse of this (links from Earthworks to Searchworks), so it seemed prudent to have the link work both ways!

Release metadata seems to already be available in the page context (because it's used to render the schema.org metadata for records, which notes that they are available in Earthworks where appropriate):

  "includedInDataCatalog": {
    "@type": "DataCatalog",
    "name": "https://earthworks.stanford.edu"
  }

Purl bd285ct9109 is currently listed in both platforms.

We could add a simple link to the metadata (like we do for the purl), but it might be more visible/useful to render some sort of context box, like we do for collection links:

As such, this might require some design.