My Leek 1660FLG (aluminum scales anodized with the American flag) was made in September of 2007. I know that all 440A-bladed models made during or after July of 2007 were converted to Sandvik. However, there's no mention of the 420HC models. Every source I've found in this knife (1660FLG) says the blade is 420HC. It's a lot easier to sharpen than 420HC, so I'm a bit confused. What steel is in this knife?