Re-attach database to SQL Management Studio 2012 with full transaction log

Having issues trying to re-attach a database for our customer, we have no idea how it became detached.

We have a 1 month old backup so worst case we can restore to that, but I am hoping you are able to restore the database using the latest .mdf file we have which has the data they had worked on until last Friday

I receive the error attached when trying to reattach it currently. I have tried removing the log file and attaching it but I then get the 2nd error message attached