For anyone that needs one in the future I used one of these, cut down to correct length.
https://www.ebay.co.uk/itm/90-45-Degree-Rubber-Radiator-Elbow-1-Ply-EPDM-Hose-Bend-Coolant-Heater-Water-Air-/333786577940?mkcid=16&mkevt=1&_trksid=p2349624.m2548.l6249&mkrid=710-127635-2958-0
As to how long...