For the future (not really applicable with _Restore issue you had, no choice in this case), Deletion isn't really a good first option (you have none left), you are better of sending the file to the avast Chest and then investigate. The adage 'first do no harm' is very apt, don't delete, send virus to the chest and investigate.
There is no rush to delete anything from the chest, they can't do any harm there. Anything that you send to the chest you should leave there for a week or two. If after that time you have suffered no adverse effects from moving these to the chest, scan them again (inside the chest) and if they are still detected as viruses, delete them.