Got it. Galaxy Guide 6 - Tramp Freighters (1st edition) is in my hands. Picked it up on Ebay, originally thought it was the hardback edition, but the seller was in error, not going to complain too much however, even softcover it was cheap compared to Amazon or Abe Books.
Having had a little while to peruse it now I can see why it was such a popular product, taking the game in a totally different direction (the same one which Edge of the Empire would, many years later) the life of a tramp freighter captain. There are chapters on interstellar trading, speculative cargoes and drop point delivery, a section on modifying your freighter, with a selection of examples, and a little backwater of the Star Wars galaxy to play around in without too much in the way of Imperial entanglements, the Minos Cluster, with a selection of rival captains, customs officers, Rebel sympathisers and loan sharks to make life more interesting.
What is interesting actually is to compare this to the 2nd edition pdf I've got. In the first edition none of the ships have a classification other than "light freighter", "converted yacht" or "custom starshp". It's only by the second edition that they actually have the names we'd normally associate with those ships, Corellian YT-2010 and 1300 Freighters, Baudo Star Yacht and Gymsnor-3 freighter. Once again the weight of the whole Star Wars canon is in the future, here I can pick and choose as I wish, ignoring the bits that don't appeal. Very liberating.
One of the cooler ships is a YT-1300 variant with a central cockpit and three rear engines, the "Oota Goota" (means "Going Somewhere") and yes the captain is a Rodian, one of the little green guys like Greedo. Going Somewhere is right as the captain has hot-rodded his ship to the point where it could give the Millenium Falcon a good run for it's money, x0.5 Hyperspace modifier and all.
Actually one of the errors in the core rule books (corrected in the Rules Upgrade and subsequently the Rules Companion) is the hyperspace transit times, the original chart read "days", corrected later to "hours", and quite rightly too. 14 days at a standard x2 multiplier beween Tatooine and Alderaan? Not likely, not even the three and a half days the Falcon might have taken is realistic given what we saw in the film. 3-5 hours, particularly with the roundabout route Han might have plotted to avoid Imperial patrols is far more sensible.
Anyway, I'm a happy space bunny. It has been said, and quite rightly, that with just the Core Rulebook, the Sourcebook and Galaxy Guide 6 you have all you need for a damned good RPG. Well I'm going to go a bit beyond that and indeed already have. Got Cracken's Rebel Field Guide now and the much praised Tatooine Manhunt module arrived in the post today (lacking the Star Warriors scenario counters, alas, but you have to pay silly money to get a copy with those). The Tramp Freighters book is still the gem I wanted most though, and it's lived up to my expectations.