I know this is somewhat a done deal, and I don't know anything about who said or didn't say and libeling and what have you....But,
Somewhat as voice in the wilderness..,to borrow a line from a NASA scientist in a famous letter, I firmly believe this IS an actual screen used ESB, just for the following reasons:
1. While it may not be scientific, I have been searching the internet since it's early days for images of Vader helmets, and have also been collecting printed materials since 1977, as well as attending several tour appearances, the first in '77 in which I thought I would see a joke, but was amazed when Vader looked authentically real, like he just stepped out of the movie. (I now know it was Kermit E. in the real suit).
The only picture I could find.
And again in 1983 at a Toys R Us, where thanks to a friend who worked there, I got up close and personal with the costume/helmet, both times taking a bunch of pics. I wore those pics out studying them and now only have a couple of them left. unfortunately, I was a stupid teenager who didn't think to keep the negatives, just in case I wanted to print 8x10s 30 years later,
Now why would I want to do that? As well as personal appearances, I have also attended and photographed several 'real deal' exhibits.
.....SO, over 35 years time I have developed a very discriminating eye for what looks right and what does not. There is not one single helmet on the Fanmade helmet list or authentic cast thread (except the MP), that I would ever mistake for the 'real deal'. There is something about an 'original production helmet', ANH, ESB or ROTJ that never seems to translate to the replicas. Even the best of them always have something that isn't quite right.
2. Like the ANH helmets/suits, I believe that some of the ESB production helmets were pressed into service as 'Return of the Jedi' tour helmets. Just like the helmet below. IT is clearly NOT an ROTJ helmet. All of the original ROTJ helmets still exist and are accounted for, and this is not one of them. The dome center strip has a visible depression at the tip, the paint layout is consistent with the ESB helmets, with the whisker color opposite the above cheek face, the cheek color continued on to the side of the nose and the larger grill work (both are details seen on some ESB helmets). I call this helmet, 'The ESB/ROTJ Conversion'. It is clearly a production used helmet, but is not quite one or the other. But despite the modifications, it clearly still has the 'real deal' look. And no one disputes it's authenticity.
The PIH's appearance is consistent with this CONVERTED detailing.
3. The PIH strongly resembles several helmet shots in the ESB. While I can't say absolutely that it IS one of these, it has many features in common to both of these. The nose paint on the right image and damage to the base of the neck, The scratches on the dome matches the pattern of mud on the left, The scratches could very well be from that 'rolling' incident. All three helmets have the same cheek to nose design and paint layout 'masked out' and this paint pattern is also consistant with my Toys R Us Vader. The chin grill has that same flat darker recessed look all as well. The only thing that doesn't seem to match is the nose paint on the muddy helmet, but this might be due to lighting.
4. As I said before, I believe some, not all, ESB helmets saw duty for the ROTJ cause. I am pretty much 100% sure that this is the helmet I saw and got close to back in 1983 at Toys R Us. (which I use for my avatar.) I had very clear pics that I destroyed studying them and only have some of the lesser pics left. I know that this would only indicate the helmet is a tour helmet but clearly a Lucasfilm production helmet. The helmet was missing a tusk and yes I tried to paint one on. (29 years ago)....It was also dented in the same spot next to the missing tusk. It also had the same scratches on the forehead of the dome, and if you look hard, they are visible in these pics. As to the paint, it was not repainted. Someone at some point later down the road, tried to re-gloss clear coat the helmet and did a very bad job. All the lines you see criss-crossing the face are where the gloss-clear is running all over, plus the build up of excess gloss-clear at the tip if the dome centerstrip, again changing its appearance. I took 24 pictures of the Vader costume that day and a dozen were very clear and sharp images of the helmet. There was not much of a turn out that day so he pretty much spent the hour posing for me. Sadly the guy inside the suit was not quite 6' tall and did not fit it well. But it was all there and looked 100% authentic.
Even if they did put the belt on upside down and all wonky. To sum it up, I feel the PIH/Farmer helmet is the same helmet I saw in 1983. And just like the 'conversion' helmet at the top, I feel it is an ESB helmet, that was modified to look more like the ROTJ helmet for for touring duty. I think after touring duty, it ended up in private hands and at some time, probably years later, in an attempt to preserve or restore it, someone 'can' sprayed it with gloss-clear and then stopped messing with it before they damaged it further.