No stone unturned - i like your style Mike.
I think you will find the correct spelling is "Marzovilla".
"Craig Jacobs" and "Stephen Marzovilla" were aliases of "Scott Nicholas Errico".
Scott was heavily involved in very large scale drug importing to USA.
And definitely his USA based firm were very involved in many murders.
Like you i would seriously like to know why he was linked to the Bamber case.
Here is one link to get you started :
http://www.pbs.org/wgbh/pages/frontline/shows/drugs/archive/whoprofits.html
This one is in French but can easily be translated :
https://webcache.googleusercontent.com/search?q=cache:yqIwK4DGZmoJ:https://issuu.com/taolkurun/docs/les_blanchisseurs+&cd=1&hl=en&ct=clnk&gl=uk
Let us know how you get on researching this one.
When i looked into Stefanos war time revenge claims i came up with a strong suspect - a major Hollywood drug dealer - so let me know if you find any Hollywood links 
Scott Errico was arrested at Heathrow airport (about to fly to Spain) on 5th September 1985.
Scotland Yard had been following him in England.
It appears he gave a lot of information to the English Police about drugs and money laundering.
The entry in the Bamber log was from 12th September 1985.
This was 7 days after his arrest.
It is therefore likely that he mentioned something to Police that somehow related to the Bamber case.
What on earth could that have been ?
He was taken back to the USA where he was from and convicted of at least 2 murders.
He had shot his two victims - he was an enforcer / hitman for a Florida drug smuggling gang.
It appears Scott and his gang were involved in laundering theirs and other peoples money.
It was believed they laundered some of the Brinks Mat gold.
The gang extensively used British based banks to launder their money.
They also used British territories for example isle of man banks etc.
Why does the Bamber log use his 2 aliases and not his real name ?
Scotland Yard knew those 2 names were aliases of Sotts well before the Bamber log entry.
Why did the message come from the Police press office ?
Was DS M Beaveridge an Essex Policeman or a Scotland Yard officer ?
Where is DS M Beaveridge now ?
What does he know ?
Anyone else's thoughts ideas or research on the above would be interesting ...