The correct approach for dealing with this type of question is a Historical Lock.

From the Meta.SE post:

A historical lock is a mechanism by which moderators can mark posts as historical artifacts.

 

A historical lock preserves older content that was very popular when it was originally posted, but is now off-topic or otherwise out of scope for the site it is posted on. Historically locking a post ends the debate over whether a question should be kept on the site or deleted, and is often the final state of a question that has been deleted and undeleted more than once.

Going further into the criteria for applying a Historical Lock, this specific question meets all of them:

1. The post is Off-Topic or Not Constructive.
   I don't think we need to argue about that; most of us would VTC this question if we saw it in the review queue today.

2. The post is stellar, in spite of its off-topic nature.
   The number of highly voted answers is evidence of this.

3. There are a large number of views, upvotes and inbound links on the post.
   Over 6000 views and still active today.

4. The post is contentious; i.e. it has been closed and reopened at least once, or deleted and undeleted at least once.
   The comments provide evidence that the question had attracted close votes, but yet there are none registered for it now. Therefore it must have gone through the close/reopen cycle at least once.

I've flagged it accordingly.

The correct approach for dealing with this type of question is a Historical Lock.

From the Meta.SE post:

A historical lock is a mechanism by which moderators can mark posts as historical artifacts.

A historical lock preserves older content that was very popular when it was originally posted, but is now off-topic or otherwise out of scope for the site it is posted on. Historically locking a post ends the debate over whether a question should be kept on the site or deleted, and is often the final state of a question that has been deleted and undeleted more than once.

Going further into the criteria for applying a Historical Lock, this specific question meets all of them:

1. The post is Off-Topic or Not Constructive.
   I don't think we need to argue about that; most of us would VTC this question if we saw it in the review queue today.

2. The post is stellar, in spite of its off-topic nature.
   The number of highly voted answers is evidence of this.

3. There are a large number of views, upvotes and inbound links on the post.
   Over 6000 views and still active today.

4. The post is contentious; i.e. it has been closed and reopened at least once, or deleted and undeleted at least once.
   The comments provide evidence that the question had attracted close votes, but yet there are none registered for it now. Therefore it must have gone through the close/reopen cycle at least once.

I've flagged it accordingly.

The correct approach for dealing with this type of question is a Historical Lock.

From the Meta.SE post:

A historical lock is a mechanism by which moderators can mark posts as historical artifacts.

A historical lock preserves older content that was very popular when it was originally posted, but is now off-topic or otherwise out of scope for the site it is posted on. Historically locking a post ends the debate over whether a question should be kept on the site or deleted, and is often the final state of a question that has been deleted and undeleted more than once.

Going further into the criteria for applying a Historical Lock, this specific question meets all of them:

1. The post is Off-Topic or Not Constructive.
   I don't think we need to argue about that; most of us would VTC this question if we saw it in the review queue today.

2. The post is stellar, in spite of its off-topic nature.
   The number of highly voted answers is evidence of this.

3. There are a large number of views, upvotes and inbound links on the post.
   Over 6000 views and still active today.

4. The post is contentious; i.e. it has been closed and reopened at least once, or deleted and undeleted at least once.
   The comments provide evidence that the question had attracted close votes, but yet there are none registered for it now. Therefore it must have gone through the close/reopen cycle at least once.

I've flagged it accordingly.

The correct approach for dealing with this type of question is a Historical Lock.

From the Meta.SE post:

A historical lock is a mechanism by which moderators can mark posts as historical artifacts.

A historical lock preserves older content that was very popular when it was originally posted, but is now off-topic or otherwise out of scope for the site it is posted on. Historically locking a post ends the debate over whether a question should be kept on the site or deleted, and is often the final state of a question that has been deleted and undeleted more than once.

Going further into the criteria for applying a Historical Lock, this specific question meets all of them:

1. The post is Off-Topic or Not Constructive.
   I don't think we need to argue about that; most of us would VTC this question if we saw it in the review queue today.

2. The post is stellar, in spite of its off-topic nature.
   The number of highly voted answers is evidence of this.

3. There are a large number of views, upvotes and inbound links on the post.
   Over 6000 views and still active today.

4. The post is contentious; i.e. it has been closed and reopened at least once, or deleted and undeleted at least once.
   The comments provide evidence that the question had attracted close votes, but yet there are none registered for it now. Therefore it must have gone through the close/reopen cycle at least once.

I've flagged it accordingly.