The outer jacket might be tefzel rather than teflon. The teflon jackets are generally teflon wrapped, like the milspec silverclad copper. Tefzel is a whole extruded jacket like pvc. It's also what was used on the AudioMagic Hyperconductor cables, which I used to have and which predated my Segue cables and the Bumblebee cables.
I got some milspec stock of tefzel jacketed cable with internal teflon insulators on the wires inside. Way nicer to make cables with!! Way easier than the teflon tape to remove and make the cables.
Anyway, tefzel is very much like teflon (ETFE vs PTFE) and has many of the same properties -- slipperiness, meltpoint, etc. If the outer jacket is very slippery and difficult to melt, it probably is tefzel.
I might want to split some of this cable with you if you're game Chuck. From the pic, it might well be the milspec silverclad copper cable with internal teflon on the wires and tefzel on the jacket. Nice cable, and a very nice profile.
How stiff is it btw? More like the typical milspec silver teflon cable, or more like the Belden 1804b?