Malvern was still called "Motosport Trails" when I raced there in the late 80's.
I can't remember the exact details, but I remember the track we know as Malvern closing for a period, and Motosport Trails moved to a different location, which was eventually renamed as what we all remember as Spring Valley. I remember racing in 1989 at the Spring Valley location with the name Motosport Trails still in place.
Then later Malvern reopened as 'Malvern MX" like we know it today, and I believe that was when the trees were gone, the big landfill mountain was in the background, etc.
Anyone know why the Malvern track location closed for several years?