- The question was closed about a month ago.
- It was closed as off topic since it falls under "recommend or find a tool, library or favorite off-site resource" which are no longer on topic in Stack Overflow.
- It was deleted yesterday after getting five delete votes from 10K+ users.
- True, while one can see his/her own deleted question having a direct link, it's not listed the question list in his/her profile.
- The +50 rep is because of an old bounty you placed over two years ago, bounty points are revoked when the question is deleted.
- You don't see the +50 in the reputation history because the question is deleted, try ticking the "show removed posts" checkbox and you should see it.
Also worth to mention you keep the reputation earned before the question was turned to CW, since it has score of more than 3 and was visible on the site for more than 30 days. (Source - search for "if you’ve contributed something worthwhile to the site, you should keep the reputation")