It's all stuff he posted on twitter and it got a lot of likes and retweets, don't know if this was planned to be a book in the first place since it's basically just a collection of drawings and not like a storyline. But it's nice that artists post more of their work for free through incentives of all these new japanese crowdfunding platforms.
@megabondagemon It's not a sample. It is everything minus two white pages at the front and back matter.
@beya He did the same thing with his c93 book. He puts a lot of trust into the fans who support him I think. It could also be he is experimenting to see how much it affects sales.
The artist comment above: C94、3日目H-23bにて発行予定の16Pフルカラーエロ漫画です。 Translates to: This is the full color 16 pages ero manga scheduled to appear on day three of C94 at booth H-23b.
The convention, as far as I understand, is that the "full color 16 pages" is only counting story pages, i.e. not counting the color front cover. This upload only has 11 full color story pages.
No it most certainly is the final version as how he named the files in the ZIP he uploaded to his fantia. It skips page 2 and 15 in the naming(the front and back matter dividers) and the rest are numbered 1-16. You can download it on his fantia for free.