A deeper, older connection to Alien?

Forgive me if someone has discussed this before, but I have a hunch that Ridley Scott already had some of the backstory from Prometheus in mind when he made Alien. One thing I always wondered after watching that film was that why would the Company be so adamant on getting "it" back when they didn't even know what "it" was? Now it is my guess that as per whatever happened with the Prometheus, the Company has all the details and records and they know about the Alien. Just not where the ship and the eggs were, so as soon as they received info about the beacon, they realized what it was and sent the Nostromo after it. What does everyone think?