I believe there is a way you can adjust your line tool to 'print' a series of dots at set intervals.
This is how many, such as Fencer (who suggested this to me), save time doing thier rivets.
I should investigate the line tool in Photoshop but I've never gotten around to it.
The way I have done it is to copy and paste a lot of it.
You'll need to merge your layers regularly so that you don't end up with 5 million layers of rivets but other than that.... it's pretty simple.
Once you've done the black rivets you can just 'load selection', move the selection down 1 pixel and fill that white. That will dupilcate what you've done and make it white.