I've seen lots and lots of Schrade knife sheaths for sale at knife and guns shows, boxes of 'em. Also available on ebay, but it's difficult to configure your ebay search for 'sheath' only. As you write, might be possible to darken the entire sheath to match the spots, you could practice on the backside of it.
By the way, Jesse... It appears you are going to stay with us... fantastic, but a little ceremony here is in order. Our Don Luis will provide the socks and ElLobo the ping pong balls. I tap thee on the shoulder three times with my blunt tipped Schrade Extreme Bomb Tech Knife, and you are an official member of 'Uncle Henry's Lost Souls'. It appears that you, like Rev jch, are also a man of the cloth, so now we have 2 chaplains. The Schrade forum here continues to thrive...
Phil