Mmmmm... I'm not very sure what to advice.
I updated from the first version when my husband gifted the Scriba to me, and did not notice any change.Then, I updated to another version that they have retired, because it was giving a lot of trouble, and now, two weeks ago, I updated to the new 2.53.2.
The firmware in your N516 is old? Perhaps if your firmware is old, better to update from the two files.
If the N516 is compatible like all people say, updating one and then another wouldn't be a trouble.
I'm very happy with this update, the reader works better, I have more options to read (now it reads mobi), and it looks a little faster. Hope it will work with yours.