I couldn't find the set here by his pixiv's name, and I think the quality is good enough to be shared.
About the files, it's a little bit too much, I know, but that's what makes it so good as guro. "Grotesch" art tries very hard to elicit emotional responses on people and I think this one does it particularly well. And well, isn't that the main objective of art in general? To get an emotional reaction? Positive or negative, emotions are emotions.