Not a bad job, considering you're using a template.
Things I'd think about:
When we present a list of information, either a "ul" or "li" in your html, left-align the content of the list and alphabetize it, putting the items with numbers at the top or end of the list. I'd put them at the top. When we center content in lists like that it just makes it harder to scan the list. When it's all over to the left, the eye can just track right on down the bullets and bob's your uncle...
For that matter, make all text left-aligned. It just makes it that much easier to read. And not to be snarky, but when I see a page with all of its content centered, it just screams "amateur." You may have to play with placement or chunking the data so that you get more paragraphs, but this will improve the readability of the content. And don't go overboard with words if you find your pages suddenly seeming empty. Short, concise, informative bits of text can be scanned and digested quickly. Whereas massive paragraphs (such as what I'm doing here...) take some time to get through. You're better off with short and direct.
On each page you've got a page title, such as "Machines", "Design", etc. Change the type to mixed case (first letter is the only cap). Even on a web site, all caps kinda seems like shouting. Also, ensure that all of those labels are set in the same size typeface. I can't be certain, but it seemed as if on one or two of the pages, the size was different. Worth a check.
Also, in regard to the header element, make is similar on all pages. It feels a little jarring when navigating the pages that the format changes on many of the pages. You'll have the word for the page title (machines) and then an accompanying image -- preferably a smallish thumbnail.
And horizontal rules aren't really all that necessary. Here's a general rule I follow: if there's an element on the page that is not informing the reader/user, then it's not necessary. Some may argue with this but it works for me... It's kinda like a lawyer editing out adjectives...
On the history page there's a photo of three guys -- is this the bowling team, the drinking team, three guys you met at karaoke? Give it a caption. (yes, I know that if I read the paragraph below I'll get this info but a caption would be a very good thing...) For that matter, take the time and give all of your images a simple caption. You don't have to write paragraphs, just a quick bit about what's going on.
If you can't give an image a decent caption, if it's not really providing some sort of additional, useful info, then you can ask yourself if the image should even be there. I'd set the captions in a type size just a little smaller than the content on the pages and perhaps use a dark grey for the type. The captions shouldn't shout, but if a reader wants to see them, they should be able to do so.
I only just discovered that I could click on images to see it larger. It might be helpful to provide a small hint that this is possible. Granted, you're using some sort of "mouse-over" indicator on the images which is what clued me in, but if I read it right there on the page, I'd know right away and wouldn't have to hunt.
There might be more but I don't want to come off like a total critical tool. I do software interface design for a living, too, though I'm paid handsomely by a large hardware and software corporation, so I don't mind giving you some freebies. I hope some of this is useful. And finally, remember that if everything on a page is bold, nothing is bold.