I have found another “book” by Les Veitch (see Ebay listing
here).
Entitled “SUTC Diecast Aircraft Guide”, the cover carried the words ‘desktop publishing’, suggesting a small, possibly on-demand, print run. Furthermore, the book apparently consists of colour pictures in a plastic folder/binder. (According to the listing, SUTC is/was the Shanghai Universal Toy Company. It produces/produced a range of diecast aircraft the same size and design as the Matchbox SkyBuster series. Apparently the SUTC models were made by Universal Toys exclusively for the Chinese market.)
My guess is that the elusive SkyBusters book was probably produced in much the same way as the SUTC volume, making it nigh on impossible to track down a copy.