creating film borders in PS

I am scanning the negatives of some rather raw b/w pics I took a while ago. I originally printed them in a conventional darkroom and, since it seemed to befit the subject matter, used a filed down neg holder to create those rough borders where you can see the film edge and sprocket holes. I don't have those prints anymore (so I can't use a scan from a flatbed scanner) but would like to add those borders to my digital prints as well. How can I do that? Can you download fake borders anywhere?

I suggest you draw them, depends on how big the images are going to be...It can get kinda difficult to get 100% realism on the borders if the images are really big, but for smaller images some PS-magic might do the trick.. :D