Ken Begg was the name used by the author Ken McClure who has gone on to publish a number of medical thrillers including a Dr Steven Dunbar series.
The Anvil Agreement has not been republished but there is Kindle version of The Anvil by Ken McClure who says on the Amazon page
"This title, my first medical thriller, was published in much abbreviated form in 1985 by Pluto Crime in the UK. Its title at that time was The Anvil Agreement and I was using the author name, Ken Begg. Plans to publish the full version fell through but now, thanks to Kindle, it is available."