Deleting orphaned shared folder snapshots

[Gremlin]

Like others before me I have found excessive disk usage under "Others". Most of this appears to be old folder snapshots that cannot be removed. These do not appear in snapshot list (when snapshots app is installed). All the snapshots that did appear have been removed sucessfully. These appear to be older snapshots for folders that were set up under names that are no longer used (going back to Nov/Dec last year).

These files are shown as owned by the admin user.

Trying to remove them manually (as the admin user, using basic tools) is not successful as they are shown as "read only file system".

Any way I can simply remove these files to clean up the system?

[Gremlin]

Never Mind - I found a solution.

I took the names of the missing shared folders as found in the 'orphaned' list (sh login; 'ls' contents of @snapshot folder) and recreated the folders exactly as they were (Capitals and miss-spelling as required!).
Re-installed snapshot app.
Recreated snapshots for the 'orphan' folders
Listed snapshots (Snapshot list) and there they were.
Deleted snapshot files
Deleted snapshot settings
Cleaned up folders.

I also found something similar for Volume Snapshots.
When originally finding my way around TNAS, I set up some volume snapshots under different names.
Later I made some changes and used different names for snapshot lists, but the old lists remained on the system.
Had to recreate those lists individually (warts and all as per @sysSnapShoot folder)
Delete found snapshots
Rinse and repeat as needed until they were all cleaned up.

In all, I recovered approx 1.5Tb of space on a 4Tb volume. Who says snapshots don't take up much space?