I remember the ME163 mainly because of the extremely reactive fuels it used. I didn’t know until now that it had gone transonic. According to Wikipedia, the aircraft landed after that 700 mph flight with almost all of the vertical rudder surface broken away from flutter. The wing sweep stemmed from its tailless nature and the need to balance the centre of gravity and centre of lift positions for stability purposes, not from any high speed aerodynamic requirements
There is one in the Australia War Memorial in Canberra. It was captured by the British, taken to England for evaluation and presented to the Australian government in 1946.