There was one inconsistency that I saw. Luke and Ben are at Ben's home and Ben is starting to open a chest and he was speaking to Luke that Anakin wanted to give Luke his lightsaber.
Where in III did Anakin say that? No where. After Ben defeated Anakin, Ben did pick up Anakin's lightsaber, but Anakin didn't say anything about giving his lightsaber to his son, Luke. Heck, he didn't even know that he had a son, or twins at that moment of time!
Am I right about this or am I tripping? LoL
Perhaps not in the script, but it makes sense that he might have said it in passing to Obi Wan at some point in time, before he ever had a son and when his intention was for good.
I don't see it so much as an inconsistency. I see it more as an omission.
You recall in Empire Strikes Back wherein Luke declares to Obi Wan, 'you told me Vader killed my father', and then Obi Wan goes on to say that in a manner of speaking, Vader did kill Anakin. It would seem Obi Wan has a way of bending the truth to fit his agenda.
In Episode IV, Obi Wan may have told Luke that Anakin wanted to give Luke his lightsaber because it fit an agenda to move Luke along the path to becoming a Jedi. Also, since Obi Wan thought of Anakin as a brother, he may have thought of Luke as his nephew or son.
"Am I right about this or am I tripping? LoL"
I think the 'vader is luke's father' plot actually was part of the background of the first movie (lucas has always claimed so, and it fits), so presumably the kenobi hesitation when asked how lukes father died, along with the outright lie about the origin of that light saber, were actually meant to be lies and not just lucas doing crappy writing for the prequels.
That's just old Obi-Wan lying, as is his habit.
I also saw Episode 4 directly after 3.
The instant I saw Ben tell Luke Anakin wanted him to have the lightsaber, I thought, Ben lied to him to get him on side. He knew Luke was the key to overthrowing the Empire and it was a convenient way to place emotional pressure on him to take an active part in the rebellion.
Remember, in the same scene Ben lied to Luke, telling him Darth Vader killed Anakin.