I had to recovery a master database in production recently and used this blog as guidance, it worked an absolute treat.

http://blogs.technet.com/b/fort_sql/archive/2011/02/01/the-easiest-way-to-rebuild-the-sql-server-master-database.aspx

It's a possible approach to verifying production master, model and msdb backups maybe? Restore the backups to another, test instance to new user databases called master_live, model_live, msdb_live using WITH MOVE.

Regards