If I'm reading this right, the last 49 bus leaves Avebury at 8:36 pm (M-F). But the last stop in Swindom is Fleming Way, Stop Y. From Google maps it looks like it is just a 15 minute walk from that stop to the Train Station.
Bus gets to Fleming Y about 9pm so will still have about 15 min of light? Is this easy walk? Was I even reading schedule and map right?