I don’t know a whole lot about these two wildcats except what the original owner told me. He lived in New Mexico and did a lot of experimenting with unusual ideas before his eyesight began to fail and he had to dispose of his collection.
On the right is a cartridge that he called the .300 Giraffe. He claimed that he was able to get the entire powder charge to burn in the case resulting in a nearly silent cartridge.
On the left is one that he called the Versa-Wildcat. By trimming the case back to the appropriate length you could make a wildcat in any one of 5 different calibers.
Both of these are outside of my collecting interest and I will consider trades or cash sale if anyone is interested.