Not sure if this has been previously suggested or not but I recently travelled this line and reckon it would make a good route in TSW. You have end to end running between Newcastle and Carlisle. If it’s set in the late 1980s you can have both Heaton carriage sidings and Gateshead locomotive depot at Newcastle. The line could support a mix of different traffic - services which stop at all stations and those which only call at a few. There could be freight and rail tours. For the September timetable they could include the ECML diversions due to engineering works. There would only be Newcastle and Carlisle as built up areas, the rest is open countryside. They could model the visible parts of Hadrians Wall which is seen from the railway - they could even include collectables relating to the Romans etc. No OLE to model other than at the two termini station ends. The line is 58 miles in length which is doable. Services take between an hour 10 and and hour and a half depending on the stopping pattern. Plus if it’s set in the same era as Blackpool/Shap the Pacer can be reused and Carlisle could be a route hopping point, potentially allowing travel from Blackpool to Newcastle with route hopping.