The Greenwoods ignored the deadly use of weapons they sold
When William and Mitchell Greenwood turned their backs on the family egg business, they found profit in providing guns for criminals and even paramilitary groups.
So lucrative was the business - selling deactivated guns along with the means and knowledge to reactivate them - that William, 76, was able to buy a £185,000 farm with used bank notes.
But the other side of the enterprise, shared with his 42-year-old son, was a trail of murders linked back to them thanks to a £1m undercover police operation.
In total, it is believed 4,000 weapons made their way from the Greenwoods onto the streets and into paramilitary arms stores.
The firearms, including automatic pistols, machine guns and assault rifles, had been deactivated and deemed safe under current Home Office legislation, but were quickly and cheaply converted back to their lethal state with the help of the former egg salesmen.
Police first raided the Greenwood's home and workshop in 1994, finding a large cache of Uzi sub-machine guns, AK47 assault rifles and automatic pistols.
Officers also found a bazooka propped up against a fridge, as well as ammunition.
The pair received suspended jail sentences for the illegal possession of firearms, but instead of disposing of their stock, as ordered by the court, they advertised the now deactivated guns in trade magazines - along with the means to reactivate the weapons.
By turning a blind eye to the intentions of purchasers, they built up a loyal customer base among the criminal underworld.
Among them was a former special constable, Anthony Mitchell, who bought 400 guns from the Greenwoods.
He then sold them on to criminal gangs, with some of these firearms being used in shootings in Dublin, Manchester, Glasgow and London.
Meanwhile another Greenwood customer, former soldier William Thompson, was found with reactivated Uzi sub-machine guns.
Thompson had links with the Ulster Volunteer Force, Ulster Freedom Fighters and Loyalist Volunteer Force.
The Greenwoods, who had been in business since 1974, were finally caught in an undercover operation which police ran during 1998 and 1999.
Police believe 3,000 reactivated Greenwood weapons remain at large
The pair were convicted on Monday at Derby Crown Court of illegally supplying firearms and have been told they are likely to be jailed.
After the trial, Detective Inspector Dick Severns said: "It seemed they had nothing else other than their love of guns. It has been
the only real livelihood for the family.
"Though they claimed that they warned customers about the law, the truth is that they knew what was happening to the weapons and didn't care where the guns would end up."
It is believed that as many as 3,000 of their weapons remain in circulation.
Senior police officers are now seeking discussions with the Government in the hope of amending laws which, they say, do little to prevent the trade in illegal weapons.