There are two things which this listing states your knife must have in order to be compatible with the OG scales. It has to have the 1/4" RAM-LOK (earlier versions had a slightly taller lock) and it has to have the forward body screws on either side of the lock (current versions have four body screws per side, early versions had only two per side). Not mentioned but the early Stitches also had a different style pocket clip from the current production. Well, I have one of the newer Stiches with the smaller RAM-LOK, and four body screws per side, and the current style pocket clip, I should be good to go. I had my knife completely disassembled, and had started rebuilding with the OG scales when I discovered there is one more compatibility factor that is not mentioned anywhere. These OG scales are a direct replacement for current model Stitches WITH G10 SCALES only. I have a current production Stitch with factory ALUMINUM scales. And Microtech made one small change between the two. On G10 Stitches, there is a metal plate on the inside of the scale that the pocket clip screws into. On Aluminum Stiches there is no need for this receiving plate, the aluminum is simply drilled and tapped and the pocket clip screws directly into it. So if you have an Aluminum Stitch and are swapping for OG scales, everything will fit and go together perfectly until you get to the pocket clip. Then you'll be left with a big hole in your scale, and no way to actually mount the clip. I disassembled everything again and reassembled with the stock factory aluminum... and THEN I realized I might have a workaround. I went and checked and the pocket clip on current production Stitches is identical to the clip on the MSI. I have an MSI with polymer handles, which uses the exact same receiver plates on the inside, and of course I put OG scales on that polymer MSI, so that left me with an extra plate that I could cannibalize. Problem solved for me, but unless you also have a spare lying around, be aware. Note for the OG crew-- I'm guessing that people will run into this exact same problem with the OG scales for the MSI, if they are trying to mount on an MSI with factory aluminum scales. There's no mention of this on your MSI listing either, so you may want to confirm and make a note that it's direct replacement for polymer and G10 MSI only.