The nails on the hinge of the right foot started to pull out and I did lose one nail (red arrow in photo above). I think it might be due to the tacks being too short, but I originally chose that length since I was worried longer nails would cause the wood to split. I also noticed small cracks have developed along the edge of the wood where the tacks are located. We will see if additional wear causes the cracks to expand.
I also felt the leather strap around my ankle is stretching a bit, but it didn't affect my walking. The leather strip around the sides of the pattens also stretched, especially around the hinge area, but it had no impact on my walking, either.
I am planning on replacing the missing nail with one that is a bit longer to see if that holds the hinge in place. If it works well, I may decide to replace additional nails.
Shortly after I made these pattens, I was speaking with someone (I just can't remember who!) and they pointed out that the London finds had been worn and the wood base would have been thicker on new pattens. This observation seems painfully obvious now, but hindsight is 20/20! If I have more problems with the wooden bases, I will replace them with a thicker wood to more accurately replicate new pattens, which will also allow me to use longer nails to hold the leather.
Overall, I am very pleased with how they held up! Having limited leather and woodworking experience, I was curious to see how they lasted with a real workout. I call this a success!