It certainly makes sense to indicate which version you are expecting to delete, especially since you can still update a resource to "undelete" it, so we're talking multiple versions here. However, the definition of the Content-Location header states:
The Content-Location entity-header field MAY be used to supply the resource location for the entity enclosed in the message
and with a DELETE, we do not encode an entity. So, I wonder whether this is allowed. It's worth bringing this up for discussion on the HL7 FHIR site and/or gForge though.