I was very fortunate that a fellow forum member reached out with a spare set he offered up to me. I am reluctant to say, but if you choose to, Reeder Custom Guns lists them on their website. I was also told to check in with some of the silhouette shooters as they were quite fond of them too. I have not been able to find a true U-notch blade, these are V-notch style blades. I'm on the hunt for just a blank blade so as I could file in my own U-notch. If you should happen to come across any of these, please keep me in mind and if I come across another set of the sight you're after I'll let you know.