NacelleStrake
Birmingham ATC can provide details of the MOSUN procedures [bit lengthy for this post]. In the near future the service may be provided by "Western Radar"...a NATS unit which provides ATSOCAS in various bits of sky in the South and West up to FL195 [FL245 in an active TRA]. I should mention the small-print and advise that the route is outside controlled airspace.
Talk to you soon maybe!