Impossible to delete backup files placed on a share via RSYNC

I must be missing something in the permissions - hoping someone can help.

Have been trying to set up a dual RN314 and RN202 system to create automated backups.  RN314 is the primary file server.  RN202 is exclusively for backups.  Both systems are runniing latest OS6.4.2.  I'm accessing all systems with Mac OS 10.11.4 on MacBook Air

I ended up changing my share structure on the 314 after I'd done a few RSYNC backups to the 202.  Thus source NAS share names changed and target backup locations changed.  

Now I have files placed on the RN202 by RSYNC backup routine from the RN314 that I'd dearly love to delete (in their entirety) but these files are proving impossible to remove via the Mac "Finder" "Move to Trash" routine due to the following error - "The operation can’t be completed because you don’t have permission to access some of the items."

In attempting to do these deletions, I"m logged into the share as the Admin.  

When I go to the settings window for this share ...

- Network access tab shows read/write access for "Everyone", "Admin" and check mark on "Allow Anonymous..."

- File access tab for this share shows Folder Admin=Owner / Folder Group=Users / "Grant rename and delete priviledges to non-owners..." is checked / Everyone, Folder Owner, Group Owner, Admin have read/write access.

I arrive at these settings based on multiple conversation threads I've found here and elsewhere.

But nothing is allowing me to delete about 250MB of music files that I really don't want clogging up my system.  

Any suggestions on how to remove files that were place on a share by RSYNC in a backup routine???