I have an old router (Comtrend ct5365) on which I had OpenWRT 10.03.1 (backfire) installed a couple of years or more ago. After making some changes to the configuration the router stopped responding. I tried to rewrite the firmware with the images available at: http://archive.openwrt.org/backfire/10.03.1/brcm63xx/ (I tried openwrt-96348***squashfs-cfe.bin and openwrt-CT536***-squashfs-cfe.bin) and I can't get the router to work. At https://wiki.openwrt.org/toh/comtrend/ct5365 it says that the correct firmware is openwrt-brcm63xx-generic-CT-5365-squashfs-cfe.bin but I can't find it in the repository.
You're going to have some challenges with a device with only 4 MB of flash and 16 MB of RAM that runs a 240 MHz CPU. Given those specs, it's unlikely that the wiki page is getting many updates so still links to ancient firmware.
You might try building your own image either with the SDK or full build chain. Even in a semi-protected situation like an internal-only DHCP server, I wouldn't be comfortable running that old a kernel and version of dnsmasq
I don't own one, and keep trying to find an "excuse" to buy one, but I've been tempted by the GL.iNet devices several times. To be very clear, I don't have any personal experience with them.