I think a lot of us use what is known as a "cows knee". I've made several as gifts and mine tie onto your triggerguard with a couple of leather thongs. The cows knee then comes up and over the primed flintlock and is secured with another leather thong that I wrap a couple times around a bone or pewter button. There also known as lock covers. The Leatherman sells a commercially made one for $15.00. Just google The Leatherman and you'll find one under leather accessories on their site.