1st inversion of chords and arpeggios always has the mediant (third) as the lowest note. So you could consider the arpeggios as starting on the second note you would play if you played an ordinary root position arp.
At grade VII, each arp. encompasses four octaves, both hands, so you end up at the top again on a mediant.
Google ABRSM grade 7 scales and arpeggios - there are some good videos to give you the tempo, etc. Fingering can be your own, but ABRSM publishes a book with suggested fingerings. Some arps you can consider the same fingering as if you played them as roots.
Just checked with my book - cost 7/- ! So bought well before 1971.