"It is what the ring represents... 57 years [of marriage]" he said as tears ran down his face.
"I feel gutted."
Also in the satchel was business documents and manuals that were "crucial" to his business.
Mr Tweed pleaded his satchel be returned.
"I am serving people in Tauranga," he said. "I volunteer at Street Help and help out wherever I can."
The Tauranga tradie also phoned police on June 30 after his trailer was stolen from private property off Courtney Rd.
"The trailer was loaded up with about $1000 of timber," he said. "We thought it was quite safe there, other people park there."
Mr Tweed said there had also been a number of break-ins in the area.
Tauranga Police area prevention manager Inspector Karl Wright-St Clair said police had yet to arrest anyone for the thefts.
"Anyone who witnessed the incident or may have any information is asked to contact Police.
"Police remind residents that unattended vehicles should be locked at all times and that valuables should not be left in cars or unsecured."
Mr Wright-St Clair said Courtney Rd was not an area of particular concern and reminded residents any criminal or suspicious activity, including theft, should be reported to police immediately.
The theft comes as police remind tradies to keep their work sites secure from thieves.
"The sooner police are informed of concerning activity, the quicker police can act on it."
A Mount Maunganui man, who walks his dogs daily, has noticed materials missing from demolition sites on his street from day to day.
In one case a section of rimu flooring was taken and in another, a stack of kwila decking timber set aside for re-using, went.
Police area manager for Mount Maunganui Senior Sergeant Deidre O'Donnell said thefts from sites was not just a problem for the Mount.
She was not aware of any recent reports but said items were taken from building sites at the eastern end of Papamoa a few months ago.
She said builders needed to take responsibility for keeping their sites secure.
"They also need to let us know if their gear is going missing so we can do something about it."
Tauranga Master Builders president John Calley said many of his members were installing security cameras on work sites.
"It is always a risk in isolated areas and demolition sites are usually left more exposed," he said. "But builders are becoming more vigilant and securing their sites."
Mr Calley said he was not aware of any upsurge in thefts from sites. His members were most concerned about losing their tools so kept them well guarded.
Further advice on keeping your business safe can be found at www.police.govt.nz/advice/businesses-and-organisations/protect-your-business
