This confirms for me a complaint I've always had about the Millennium Falcon. A ship equipped with hyperdrive would certainly have had targeting systems as good as a B-29. There would have been no need for the midships ladders to the gun stations.
But yeah, that scene is mostly artistic license.
Of course this is all my own rationalization: it's not like Lucas thought all the intricacies of the Star Wars universe through for their technical accuracy. This is more like literary interpretation, only instead of showing "The Old Man and the Sea" is a metaphor for the tragedy of human existence, we figure out how space ships work!
1: http://www.discovery.com/tv-shows/mythbusters/videos/star-wa...
Or something. ¯\_(ツ)_/¯
So yes, I'm pretty sure the Millenium Falcon was heavily upgraded.