Misunderstood your original post and did not realize you were asserting the period as 1530-40, distracted by the word later. As I have understood katzbalgers developed in the early years of the 16th c. around 1515, and were with the figure eight guard.
I was thinking 'later' meant several decades or more rather than a few years, as most form developments cover at least that, if not generations.
I had thought the ring guard was further into the century, but clearly not the case. It is interesting how much Italian innovations transmitted into arms throughout Europe.
I'll be adjusting my notes
