Mtdparts not saving on airRouter

I have an old airRouter which seemed bricked. I connected up a console to the jtag port and am able to access the ar7240 prompt.

First thing I notice is that the mtdparts output is missing some lines:

device nor0 <ar7240-nor0>, # parts = 6
 #: name                        size            offset          mask_flags
 0: u-boot                      0x00040000      0x00000000      0
 1: u-boot-env                  0x00010000      0x00040000      0
 2: kernel                      0x00100000      0x00050000      0
 3: rootfs                      0x00660000      0x00150000      0
 4: cfg                         0x00040000      0x007b0000      0
 5: EEPROM                      0x00010000      0x007f0000      0

Comparing with another airRouter I have that is working, I added the missing lines:

mtdparts del nor0,5
mtdparts del nor0,4
mtdparts del nor0,3
mtdparts add nor0 0x660000@0x150000 rootfs
mtdparts add nor0 0x490000@0x320000 rootfs_data
mtdparts add nor0 0x40000@0x7b0000 cfg
mtdparts add nor0 0x10000@0x7f0000 EEPROM
mtdparts add nor0 0x760000@0x40000 firmware
setenv mtdparts mtdparts=ar7240-nor0:256k(u-boot),64k@256k(u-boot-env),1m(kernel),6528k(rootfs),4672k@3200k(rootfs_data),256k(cfg),64k(EEPROM),7552k@256k(firmware)

then save the environment

saveenv

ar7240> mtdparts

device nor0 <ar7240-nor0>, # parts = 7
 #: name                        size            offset          mask_flags
 0: u-boot                      0x00040000      0x00000000      0
 1: u-boot-env                  0x00010000      0x00040000      0
 2: kernel                      0x00100000      0x00050000      0
 3: rootfs                      0x00660000      0x00150000      0
 4: rootfs_data                 0x00490000      0x00320000      0
 5: cfg                         0x00040000      0x007b0000      0
 6: EEPROM                      0x00010000      0x007f0000      0

active partition: nor0,0 - (u-boot) 0x00040000 @ 0x00000000

defaults:
mtdids  : nor0=ar7240-nor0
mtdparts: mtdparts=ar7240-nor0:256k(u-boot),64k(u-boot-env),1024k(kernel),6528k(rootfs),256k(cfg),64k(EEPROM)

load openwrt on it which seems to work, However, anything I write to the overlay filesystem goes away when I reboot! Getting back into the ar7240 prompt again, mtdparts shows it's now back to the defaults. It's as if it's not saving.

I have 6 routers which are in this state. Can they be saved?