Hi Paul,
I would not use Projects for this as they are what you may consider a pseudo-service - the actual service is generated from the definition in the project.
I'm pretty sure this information is contained in the runtime model object and should be reachable through the model object introspection. You could bind to structures prior to SEGW coming onto the scene.
On another note, I'm assuming that you client is another SAP system. I'd try and avoid coupling too much to the ABAP Dictionary. True it does expedite development, but OData is not meant to be an extension of the Dictionary, the Dictionary integration is more of a convenience than a necessity. Just wondering why you feel the need to do this?
Regards
Ron.