The work included the installation of a new crushing circuit - specifically a new primary jaw crusher and conveyor belt for the feeding of the facility's secondary cone crushers.
Winston said initial testing should start in two to three weeks.
Company chief executive Murray Nye said once online, the mill will run at 75 to 85 tonnes per day, processing lower-grade stockpile to test and tune the mill.
When targeted gold and silver recovery rates are met, it will ramp up to a throughput of about 150 tonnes daily, its nameplate capacity.
The mill has a ball milling circuit and gravity and flotation circuits. The miner has constructed a new lined settling pond for tailings disposal with a 35,000-ton capacity, and two additional ponds are also being built.
"Winston anticipates producing dore bars on-site from the gravity circuit. These bars will be sent to Idaho for refining [and] initial gold and silver concentrates will be sent to various companies for testing," he said.
Nye added that Bureau Veritas previously performed gravity and flotation tests on selected drill core from the site's Parallel, Custer and Block 93 vein systems.
"The gravity circuit alone was able to recover 5.9% gold and 1.3% silver. Flotation of the gravity tailings recovered 86.7% gold and 85% silver and resulted in a combined gravity plus floatation recovery of 92.6% gold and 86.3% silver. Bureau Veritas stated that they believed that there was still room to improve that recovery rate," he said.
The Paradine mill is located 35 miles (56 km) from the Winston gold project near Helena, Montana.