Both LMR and BWF saw Oswald carry a large bag that morning and the bag was found in the SN so there is a basis for fact.
But both BWF and LMR were shown the package supposedly found on the 6th floor and said it wasnt what Oswald carried. Also both suggest they saw it carried in a way impossible had it been the rifle. So there is also a basis for fact that Oswald didnt carry the supposed large package that was forensically examined and showed no signs of gun oil, gunpowder, nitrates, creases or scratches that could connect it with the transportation of a broken down rifle, a rifle the FBI described as "well oiled" in particular.
I dont like to say people are lying and I can agree that people can make errors when trying to recall the length of an item but Frazier observed the package being stuffed under the armpit with the bottom part cupped in his palm. That is not a guess or an estimate but an observation. He then was shown the large package and said it wasnt what Oswald had. Again, that is not a guess but a comparison based on his observations which was corroborated by Randle.
I am very suspicious of that large package any way.