How do I find or list the path that mtp assigns for mounting the device? When I enter
ps -ef | grep mtp
the report is as follows:
ericthe+ 2372 1849 0 12:51 ? 00:00:00 /usr/libexec/gvfs-mtp-volume-monitor
ericthe+ 4743 2108 0 13:10 ? 00:00:00 /usr/libexec/gvfsd-mtp --spawner :1.10 /org/gtk/gvfs/exec_spaw/5
I don't see anything there that looks like the quoted path. 
gio mount -l
only makes reference to the last previous "recognized" USB mount performed by udev automount:
Volume(0): VERB_R_F1
Type: GUnixVolume
which is reporting on the previously mounted (currently not mounted !!!) USB stick, and doesn't even list the SONY Walkman that is plugged in via the process
ericthe+ 4743 2108 0 13:10 ? 00:00:00 /usr/libexec/gvfsd-mtp --spawner :1.10 /org/gtk/gvfs/exec_spaw/5