The relic is a short stretch of railway track once part of the 57km Waimea Plains branch line, linking Gore with Lumsden and ultimately Kingston on Lake Wakatipu.
Colin Smith, spokesman for the Waimea Plains Railway Trust, says the plan is to recreate a railway operation of the 1880s, complete with locomotive, carriages and rail equipment such as points and turntables.
The trust recently took delivery of one of the "Kingston Flyers" - the American-built 1877 Rogers K92 steam locomotive originally used on the Waimea Plains line.
It also has most of the other rolling stock and equipment it needs and this year will begin laying a 4km line that will form a loop around the Croydon Vintage Aircraft company's operation.
Mr Smith describes it as a very long-term project, but one that will be unique in New Zealand.
The Waimea line was a Dunedin venture designed partly to keep gold-field trade flowing through Dunedin rather than Invercargill.
In the 1870s, the New Zealand Agricultural Company was trying to sell blocks of farmland between Gore and a location known as "The Elbow" near Lumsden.
According to the late Robert Meyer, in his book The Ships and Trains that Served Lake Wakatipu, the lack of transport was inhibiting sales, so the Waimea Plains Railway Company was formed.
The minister of public works at the time, William Larnach, of Dunedin, was one of the 22 "prominent" Dunedin men who voted to go ahead with the line in 1878.
They claimed the line would become part of the main trunk system of railways and that upset Invercargill interests promoting the line from Invercargill, through Winton, to Kingston.
Mr Meyer wrote the Waimea proposal was viewed in Southland as a "blatant attempt" by Dunedin to divert the Lake Wakatipu trade away from Invercargill and "aroused feelings of antagonism between Invercargill and Dunedin that still have not entirely subsided".
Southland newspapers claimed Dunedin had been given an "unfair advantage" and had some "very blunt things to say" about the "nefarious" actions of politicians in favouring the Waimea line.
The first sod was turned at Gore in 1879 and 300 "hands", including women and children and about 100 Chinese, had the line completed by May 1880.
The opening of the line meant Dunedin people were able to travel to Kingston in 11hrs 50min.
The line struggled financially and closed in 1933.
The goods shed at Mandeville is one of the few surviving relics and members of the trust have been busy salvaging other pieces of the country's early railway infrastructure, including a locomotive building from Dunedin.
Mr Smith said trustees "made a dash" to save old equipment as former national rail operator Toll Holdings sold off for scrap any metal that could be "torn out" of the ground.
He hoped eventually tourists would be able to enjoy short trips on Mandeville's vintage railway.
