Hi danial, I will give you our 16M flash file, this file is product file,the size is 16M.
16M file path: https://glinet-hoff-temp-file.oss-cn-shenzhen.aliyuncs.com/GL-AR750-16M-20191211-md5-f76354a5f2dd2a309809a3190041bf79.bin
You can follow below steps to flash the deivce.

  1. You can try to use your flash tool to flash the all flash file to the device.
  2. If the device can to run, you can use ssh to login the device(host: 192.168.1.1)
  3. Write your device art.bin use the liunx command, like this: mtd write /tmp/94_83_C4_0A_4F_FA-art.bin art
  4. Upgrade the standard firmware use the linux command, like this: sysupgrade -n /tmp/openwrt-ar750-3.211-1227.bin
    Standard firmware: http://download.gl-inet.com/firmware/ar750/v1/