I'm trying to recover data from an N5200 (non-Pro) which dropped two of its five 500gb WD5000abys drives. I've made images of the drives using Runtime Software's RAID Reconstructor and a USB enclosure and am trying to recover the data from the images. RAID Reconstructor is unable to determine the parameters used to create the RAID. Does anyone know the correct parameters below for an N5200 in default configuration, or how to find out (without paying a data recovery service)?

Start sector of the RAID on each individual drive?
Block size (in sectors or in KB)?
Parity rotation (choices are Forward 1-2-3, Backward 3-2-1 or Forward Dynamic Disk)?

Thanks