Recovering Raid 1 Stripe after SD corruption (RPi)

I have been running OMV 3 on an RPi 2 for some time, and today it suddenly misbehaved. Initially the web interface didn't work, then after reboot it goes into emergency mode and from there into "raising network interfaces" which runs forever with no limit. My conclusion - the SD card is fried (checks confirm this is very likely).

I need to recover the files on the Raid disks if possible (2 x 1TB). When I cut a new OMV 3 SD card and reboot, "Physical disks" can see them as sda and sdb, but "File systems" cannot. This means I cannot mount them from the web interface to retrieve the files or rebuild a more robust OMV setup. If I try to mount them myself, this fails. See below result of lsblk and attempted mount:

root@raspberrypi:~# lsblk -f
NAME        FSTYPE   LABEL       UUID                                 MOUNTPOINT
sdb         linux_ra raspberrypi:Raid1Mirror
                                 66243d3d-07e1-5847-606e-f191a34992a9
zram3       swap                 651c5e00-c9e0-401a-8ac0-6c520247b927 [SWAP]
zram1       swap                 dd347844-695b-4769-9972-e739b62b7370 [SWAP]
sda         linux_ra raspberrypi:Raid1Mirror
                                 66243d3d-07e1-5847-606e-f191a34992a9
zram2       swap                 cddd0ffa-9b66-46b4-a564-8a8e0ec6bec0 [SWAP]
zram0       swap                 46667f81-5744-480e-bfe4-bc07f6565dac [SWAP]
mmcblk0
├─mmcblk0p2 ext4                 ae708a4d-982a-4a20-965c-01ec7e1f32b3 /
├─mmcblk0p3
└─mmcblk0p1 vfat     boot        CE83-8CE1                            /boot


root@raspberrypi:~# mount -U 66243d3d-07e1-5847-606e-f191a34992a9 /media/66243d3d-07e1-5847-606e-f191a34992a9
mount: unknown filesystem type 'linux_raid_member'

As I use OMV for domestic backups, my plan is to move to 2 x RPi3 OMV 3 implementations with SSD for OMV itself plus 1 of the 2 x 1TB HDD used for backups now. Therefore if I can get help to mount the existing RAID initially so I can get the data copied somewhere else, or remove the Raid SAFELY so I can mount one of them as ext4 that would be very helpful.

Hi ryecoaaron - the assemble worked so I am able to mount the Raid1 to put the data somewhere safe so I can reformat the HDD and start again. Yes I know the RPi is not ideal but this is domestic backup plus media server so with careful planning it is good enough for now.
Many thanks again!

Hi tkaiser - I don't disagree, but in this case I have all the bits I need already and would have to take the SDDs off otherwise! I was using a good SD card and the official power supply (the 2 x HDD have own power supply) and that failed today but after about two years. I suspect the original installation didn't have the flashmemory plugin enabled whereas the new one does by default.

I am still pondering what to do when I have saved the data, but retrieving this - which will go on for several hours - was the top priority. I am not wedded to RPi, just I use them for all kinds of experiments already but something which can drive the disks SATA and has 1Gbps Ethernet would be preferable. I did look at a Synology box and that's the sort of thing that would be good, but running OMV!