Emrys is right about the two venues, but the MNR website only gives the Memorial Hall. Considering they claim that this year there will be more layouts than ever and increased trade support, it is difficult to see how they will get by with only one venue.
The Memorial Hall is easy to find. From the station, head towards the traffic lights by the level crossing. Turn left and the Memorial Hall is a short distance on the right. Easy to find and should be well signposted.
Three NG layouts are listed - Stump City, RAF Chapple (009) and Stoney End (7mm).
The exhibition is open from 10 until 4 and I should be there late morning / linchtime if you fancy a cuppa.