Recommendations for a used 4G/LTE Router which is OpenWrt friendly

It looks like I am unable to install OpenWrt on my TP-LINK Archer MR200 v4, so I'm looking to replace it with something else.

Could someone recommend a used OpenWrt friendly 4G/LTE router for the home?

The Tektronix RUT devices?

Or get any regular (openwrt supported) router with an USB port, then buy a 4g USB stick, that's what I've been using for a very long time.

You can ask for help with your router in ROOter forum.

I have an EE supplied Bright Box Wireless Router with a USB port.

Would this do?

Not sure what sort of power supply it needs. I don't think it is 12v and there is no voltage info on the unit.

Since you are not the only one and not the first one searching for such a device: Does searching the forum for LTE lead to something useful for you?

After trying about 20 different power supplies I found one which worked and have now powered up the box, but there is little info available to tell me what it is, searching for EE BrightBox found some images like my router, so I guess it is a Bright Box 1 wireless router:-

Can anyone confirm that this is the one I have? :-