I wanted a convincing back-story for the layout so here it is! It's been modified a few times as the layout design has changed, and may not yet be finished.
Originally the area was the North Wood until it was granted to the Bishop of Hereford when it became known as Bishop's Wood, later contracted to Bishopwood. A later Bishop founded a small religious house, Norwood Abbey, which was largely destroyed in the Reformation. The stones were used to build Norwood Manor and church, the remains of which can still be seen near Gale End station.
A settlement grew up near the Abbey and, due to the coal found nearby became known as Gale End (a Gale is the local term for a drift mine). Initially this coal was mined solely for local use as the cost of transport by pack horse was prohibitive. With the increased demand for coal during the Industrial Revolution there were commercial opportunities to be exploited. A tub-boat canal was built up the valley towards Gale End with horse tramways being used to carry the coal to an interchange and terminal basin near where Norwood Halt is today.
Time moved on, the tub boat canals were inefficient as they required multiple handling of the loads and were slow, so the GWR were persuaded to build a branch line to Gale End. A small passenger and goods station was built here, although the main coal sidings were further down the line. Unfortunately the canal basin was filled in during the building of these. There was a small halt built near the sidings, primarily for the workers, which was given the name of Norwood although it's some distance from the manor of that name. The railway also destroyed much of the remains of the manor, which was already derelict.
The mines in this areas were never very profitable as they didn't suit large-scale working, so the coal sidings were removed in the early 20th Century and the loading moved to Gale End. At about this time a bay platform was added to cater for regular Autotrain services. The line remained open for general traffic, and indeed increased leisure time in the 30s meant it enjoyed a brief revival with the tourist traffic. The area around Norwood Halt was popular with walkers and cyclists so the halt was rebuilt and a second platform added.
Inevitably the line fell foul of the Beeching report and was closed. Fortunately the trackbed and buildings largely survived (although the original Gale End engine shed was demolished for the stone) until a preservation group, later to become the Gale End Rail Trust (or GERT for short), was set up in the 1980s to seek the restoration of the line. By the late 1990s the remaining trackbed and buildings for Gale End and Norwood Halt had been acquired and restored, and passenger services started running again. As always with such railways there is a mixture of stock, although the aim is to restore things to the glory days of the GWR.
Longer term there are plans to extend the railway along the original route back to a terminus with the main BR lines.