In the past Buck has upgraded the blades on their 560 model using the same variety of blades as used for 110 upgrades. The 560 used the same blade as the 110, but had a thinner and lighter titanium handle. I have one with a BG42 alloy blade and I have seen them with ATS-34. The 560 is out of production, but you might find a 560 on ebay or at a pawn shop and get Buck to upgrade it for you. My 560 fits my needs better than a Buck 110. Here is what they look like: