There is a company that sells a bunch of styles:

https://bbgbashguard.com/

An option would be to cut your own out of a chainring that was a couple sizes oversized, but for a 54T, that would mean a pretty large ring. Let's see, with the circumference being pi*D, to increase the diameter by about an inch, I think one would have to increase the diameter by 3.14 inches, or about 6 or 7 teeth, so your donor ring would have to be at least a 60T, if not larger.