Unless it chronically scratched film in the past, I'd suspect the lab first. Start there. Try another roll at another lab. You'd probably be able to replace the door and/or pressure plate from a donor camera for less money than a "fix." Doubtful Nikon would have a pressure plate(most detach) unless shared with a newer model. N75s don't go for much $ now.
Originally Posted by Bluetintedescapegoat