Thank you for posting this.
The discrepancies are notable, but even within the witness statements there appear to be contradictions. For example, TN is quoted as saying "collar-length hair," but then later, "None of the 4 witnesses described a mop of hair...they spoke of shortish hair."
To me, collar-length isn't particularly short. And how thick or long would it have to be to qualify as a "mop"? There aren't any pictures (at least that I've seen) of BG from April 26 1999, but the pictures of him from around that time period mostly show him with kind of mid-length hair, not really short or particularly long. How such a hairstyle would be described is probably very dependent on the person describing it.
Besides typical witness variance, the descriptions all seem fairly similar to me: they all roughly match BG's age, height, build and hair colour, and describe a smartly-dressed man in dark clothing. It's not like one witness described a skinny man with dark dreadlocks wearing a tie-dye t-shirt, and another described a large man with a blond crew cut who was wearing Gucci. The discrepancies, such as they are, aren't huge, glaring red flags in my opinion.
Polishing a car might be the action of someone who owned the car, but it could equally be the action of a stalker/loiterer who was trying to avoid looking suspicious as they stood around in the street. Without someone coming forward to say it was them, I'm not sure anything can be gleaned from that sighting one way or the other. I also don't think it necessarily matters much that one sighting was at 7:00AM and another at 9:50AM. A person who randomly wandered the streets, as BG was known to do, could presumably be anywhere at any time.
It's not uncommon for witnesses to fail to identify people in a line-up, so I don't think that proves *or* disproves anything. Particularly as the line-ups must have been 12+ months after the killing, and the witnesses who saw the killer leaving didn't get a really good, close look at him. If I remember correctly, one was looking down from an upstairs window and the other watching from across the street?
BG lived close by, so I similarly don't think anything can be taken from the killer wearing a coat. If anything, if the sightings *were* of the same man, returning later with a coat would strongly suggest the killer had that coat easily accessible in the vicinity.