I have no access to Holland and Holland sidelock, but have examined Holland and Holland pattern intercepting sears on boxlocks, and they are exactly as you described. I think that you answered one of my questions, as to both sears possibly jarring loose, but unlikely to happen due to depth of engagement of one sear as opposed to other. It did bother me, though, that they both could possibly be jarred loose, in which case, no interception takes place, only a possible firing of both cartridges, or firing of rifle when dropped (I have never dropped a firearm in my life, but there is always a first time for everything). Thanks again for the explanation; I appreciate it. Anxious to hear if anyone else has anything to say about intercepting sears.