@ants Gave that image a try, but still the same error.
Basic Interface (non-advanced settings):
Listed at bottom of screen: Model ar300m NAND (so I think you are right on the nand version, I'll give a few more nand options a try)
Luci Interface:
Here are some details from the system:
Model: GL-AR300M
Firmware: LEDE Reboot 17.01.4 r3560-79f57e422d / LuCI lede-17.01 branch (git-17.290.79498-d3f0685)
System/Software/Configuration/Distribution Feeds: src/gz packages
http://www.gl-inet.com/lede/2.27/ar71xx/nand (so again I think you are right about the
nand memory)
Details from System Log:
Mon Apr 9 21:17:36 2018 kern.info kernel: [ 0.000000] CPU0 revision is: 00019374 (MIPS 24Kc)
Mon Apr 9 21:17:36 2018 kern.info kernel: [ 0.000000] SoC: Qualcomm Atheros QCA9533 ver 2 rev 0
Mon Apr 9 21:17:36 2018 kern.info kernel: [ 0.117209] MIPS: machine is GL-AR300M
Mon Apr 9 21:17:36 2018 kern.info kernel: [ 0.834536] nand: device found, Manufacturer ID: 0xc8, Chip ID: 0xb1
Mon Apr 9 21:17:36 2018 kern.info kernel: [ 0.841168] nand: Giga Device GD5F1GQ4U 1G 3.3V 8-bit
Mon Apr 9 21:17:36 2018 kern.info kernel: [ 0.846381] nand: 128 MiB, SLC, erase size: 128 KiB, page size: 2048, OOB size: 128
I'll keep digging around in that NAND directory at openwrt's site, maybe one of them will do the trick. Thank you for the tip on memory type differences.