The Historic Cemeteries Conservation Trust of New Zealand has raised about $350,000 to restore the tomb building's badly weathered and vandalised structure to its former Gothic elegance.
Contractors recently dug a channel for electrical cables for a sophisticated new lighting and security system at the tomb, in Dunedin's Northern Cemetery.
Test holes had been dug earlier in a nearby grass path to ensure no paupers' graves were disturbed by the trench.
Trust chairman Stewart Harvey said it had taken many years to bring the restoration project together, with its complex "jigsaw puzzle" of many elements, including replacement stonework and stained glass, as well as installation of a new security system, with sophisticated security cameras.
"It's a step forward. It's encouraging that it's all going to start rolling," he said.
The mausoleum was created by one of Dunedin's finest architects, R. A. Lawson, and echoes the appearance of First Church, which he also designed.
The tomb houses the remains of Larnach (1833-98), a prominent Dunedin businessman and MP, and his first two wives, Eliza and Mary, his eldest daughter Kate and eldest son Donald.
Stonemason and sculptor Marcus Wainwright has spent months shaping Oamaru stone blocks for the project and stained glass artist Peter Mackenzie is importing antique stained glass from France to replace smashed windows.
