Okay have dug out my Asus router, and flipped TP-Link into bridge mode and it works, the TP Link did leave wireless turned on - so plugging a cable into an Ethernet port lets you into web admin interface and can disable this.
Have taken case apart - and can confirm Broadcom chipset and the antenna are removable with pliers once you open the case and snip of the wire to each one (did not cut wires on mine

) Will add a photo to mini review on Sunday.
IPv6 seems a bit messed up in Bridge mode, so might have a longer play once other weekend work tasks are done.