I made a inquiry in regard of the Turntable remote RM -71 in which Turntable it operates , I discovered one  and purchased (new in the box)  just this week the JVC L-F71 . Both remotes function and operate the  RC M90 80 60 and my PC 5 . The instruction manual list the Turntable model  however not the portable models . 

very interesting !Great find!