Robert, a couple wraps or less of electrical tape should solve your spinning issue.
I had not heard of GaugeMate before but it looks like they are using stainless steel which is a bonus VS ShortLane's rust prone steel units.
The GuageMate's look well made that's for sure. Smart machining in extra O-ring slots in case more friction is required.
I don't know if Corwin will bring in more of the 13" Alum framed single shot's but they are way better then the DA singleshot and are quite a bit lighter which is nice for backpacking. Hollow synthetic stock where you can stash smaller adapters and supplies.
The price was reasonable too.