Cacti Intervention

I have attempted to graft a loph. I degrafted from a periskopsis a few years back, but which never grew roots. Hopefully, this will bring the little treasure back to life.  The old, personally sown, old Trich. was looking ugly anyway, and the nice bit I lobbed off should make fresh roots ready to repot next Spring. The loph would have died anyway without grafting too,  so there's nothing lost if this little intervention doesn't go to plan...