I have created a custom property called StockSize to show the sheet size of a part when flattened. Once I mirror a part to create the oppsite hand version, it loses some of the properties. Specifically the sheet metal thickness. Is there anyway to solve this. See image below.
Can't say I have experienced this exact issue, but I would recommend checking the units on both documents. The difference in thickness seems to be the exact ratio of inches to meters. (.105 * .0254 = .002667)