ok I think I have solved my invisible mouse issue.
I have startx with openbox and mouse pointer now appears, so it may be just a gremlin for my mouse in jwm?
its a gecko wired usb mouse, dmesg
[ 2.519245] input: USB OPTICAL MOUSE as /devices/platform/scb/fd500000.pcie/pci0000:00/0000:00:00.0/0000:01:00.0/usb1/1-1/1-1.3/1-1.3:1.0/0003:0000:3825.0001/input/input0
extra info.
mouse pointer was also hidden in fltk-1.3.
I then loaded openbox but not ssh session but for real on RPi and tried startx....startx claimed
/etc/sysconfig/Xserver not found.
Maybe openbox depends on X11....but anyhow I loaded Xorg and the startx works and then mouse pointer appears