Explaining Permissions Mac OS X 10.11.5 / ReadyNAS OS 6.5.0 / AFP - Second Question

Following on from my First Question - https://community.netgear.com/t5/Using-your-ReadyNAS/Explaining-Permissions-Mac-OS-X-10-11-5-ReadyNAS-OS-6-5-0-AFP/m-p/1088919/thread-id/109697

This relates to accessing my 314 running OS6.5 via AFP from OS X 10.11.5 (latest El Capitan updates in place).

This all for the user "admin" in ReadyNAS OS 6.5.  I'm logging into via AFP using the user "admin"
 
User "admin" (UID=98) primary group in FrontView is "admin" (GID=98)  and its secondary group is "users" (GID=100)

Here's what I see via SSH when I looked at the directory “test” within the share “shared” - also logged in via the user admin

 
With the exception of the file “test - new file.txt”, these are the permissions in place after moving the directories and files from the USB backup disk of my old ReadyNAS NV+.  These files were placed on the EXT3 formatted USB Backup disk but the ReadyNAS NV+ backup job, and restored to the 314 using a backup job.  I checked the backup job option “after backup is complete, change ownership of files in the backup destination”.  

Here’s what I see in FrontView for the share called “shared”

Here's what I see in the Finder for the directory “test” the share “shared”, logged in via the user admin via AFP.  Again note “test - new file.txt” was created in this direction from the OS 10.11.5 machine, where as the director and file were created back the backup job copying from the USB disk.


Can someone please explain the differences between these views...
 
(1) why is the owner of these files in the Finder "(unknown)"?  I was expecting "admin"
 
(2) why is the group of the file “test - existing file.pdf” "staff"?  I was expecting “users”

(3) why is the group of the file “test - new file.text” “staff”?  I was expecting the group of a new file created in this folder to be the primary group of the user admin i.e. admin (GID=98), or possibly “users” (GID=100) (the secondary group of user admin, inherited from the  containing folder “test”).  
 
(4) why are the permissions the file “test - new file.txt” different from “test - existing file.pdf”?  I was expecting, based on the “Default Access” settings and “Permissions” settings FrontView for this share (see screen shots above), that files created in this directory to be group Read & Write and everyone Read & Write.  

 
Thanks for everyone's help