I can't attest to all of those, but no, the DP/Rubies Scout and Boba Fett aren't 1:1. There was some shrinkage in their mould-making off the originals they were given. The Boba's shrinkage isn't massive, but noticable when placed side-by-side with a true 1:1. The Scout is a little shrinkier, such that it's only suitable for shorter/more petite people to wear without looking like pinheads. This is why the ongoing delay of the eFX Scout is so aggravating. The worst offender was the original DP Royal Guard. THat shrank so much it's egregious. When I could scrape it on over my cheeks, sitting flat on the top of my head -- no padding --- the shoulder flares hung a good two to three inches above my shoulders.. Sitting next to their actual 1:1 Rubies Supreme Royal Guard helmet, it's a massive difference. I swear, that Supreme Guard utterly astonishes me. It was so out of character for the company. It's solid, sturdy fiberglass, true 1:1, an utterly accurate recreation (save for the visor color) of the original prop, and the right color, even. Their new, injection-molded Boba Fett is even better, in that it's lightweight, durable, easy to mod, and inexpensive. Plus it retains accuracy while evening out the symmetry -- my one big gripe with most Star Wars helmets. This is why I wept tears of joy over the Black Series Stormtrooper.
But now, the Vader isn't the only helmet DP/Rubies dropped the ball on as far as scaling issues. Not by a long shot.
As for this Vader...? Hell, even as foreshortened as the neck is, I still prefer it over just how absolutely wonky the original Vader mask was. The "purists" can hate on me all they want, but from the first time I noticed how melty-swoopy the neckline of that thing was, I can't unsee it ever.
--Jonah