The number on the side of the jeep that Blackford picks Pete up in camp with is different from the number on the side of the jeep Pete says is Blackford's when he picks up Eleanor outside the cafe. Later, after their drink as the jeep drives in the rain, the number switches back to the first number. In an amazing coincidence, the jeep Eleanor later requisitions for her 3-day leave with Pete appears to be the jeep Blackford had earlier in the film (same number on hood).
Just after Frank Lovejoy (Maj.) tells William Holden (Sgt.) about his promotion to Lt.; Holden puts on a jacket with his sergeant stiles on it. They drive to a restaurant/bar (Mama Mia's) and his jacket no longer has any sign of stripes. When stripes are removed the impression of the stripes and the stitching can still be seen. His jacket is absolutely pristine. Even if the stripes came off without leaving any marks at all; there would a clean spot where the stripes were. Later, when now-Lt. Peterson is talking to Lt. MacKay in the mail room, the remnants of his old Sergeant's stripes are clearly visible on his left sleeve.