Solved it! Plumped for a "Western Digital TV Live Streaming Media Player" for £65 from amazon. Plugs into HDMI on TV and has wirelessly picked up my Mini DNLA server which is on a USB hard drive connected to the Router (Netgear 3500 with modfs and AMod custom firmware to enable media server capabilities). Working flawlessly and also has iPlayer too! Happy days.
OnePlus 5 review