McGrath Benchtop Solutions' skills were recognised by the University of Otago Anatomy Museum as perfect for polishing resin blocks containing cross-sectional and other anatomical body samples, used for teaching.
The work was required because the resin was scratched and dull after more than 30 years.
Co-owner Eloise McGrath said working on the blocks, which included cross-sections of a human torso and human head, was confronting but ''absolutely fascinating''.
The blocks were sanded and polished to allow a clear view of what was inside.
Museum curator Chris Smith said the resin blocks came from a variety of sources.
The vascular casts were made by Prof Greg Jones in Dunedin, probably in the late 1990s.
They were made by injecting coloured resin into blood vessels.
That resin cured, after which the tissue of the kidney was dissolved, leaving behind the resin cast of the blood vessels.
A series of 20 large sections of a male trunk were produced in Dunedin in 1985, while sections of a human head were developed in the 1980s at Colorado State University.
Mr Smith said the technology to produce the resin blocks was reasonably recent.
The blocks were still ''in heavy use'' for teaching.