Allfine PC703 - how to backup or restore system

Just got a new Allfine PC703, and before I start playing with it was wondering if anybody could tell me how I can back up the system image so I can restore it later if I screw anything up? Or where I can download an original system image (CE5) to replace the default one?

Can this device be reflashed from the SD slot, or do I need a JTAG cable, or what?

It can' t be reflashed using SD card, only by USB-USB cable(Or update XIP from USB stick but it doesnt boot after that). You can dump rom using "grabit_armv4" program and then later extract XIP, boot, ROM parts and reflash. Haven't tried this yet but it should be possible.
What is different from 1.9 ROM and in Allfine that you may be missing if reflashed with generic image?

give me the procedure to reflash my pc 703.thank