Further progress

Here's a bit more on this image. I've been going at it pretty hard this week. At this point, you can see that I have finished painting in the textures on two of the three prongs that hold the pipe in the middle. The bottom one is still blank; all you see on it is the layer effects. As I mentioned previously, just using them accomplishes quite a lot. For the large and small bolt holes on them, I made a smart object, then duplicated it for each one. That way, a fix to one will apply to all. The threads are based on a selection made from the pipe opening. They are actually just a series of curves spaced out evenly, not a true spiral, but I think the effect works.