Terry: A Flintlock vent plug does not need hardly any torque at all. A snug tightening with a screw driver (or hex wrench? How modern!) is all that is required. The torque I mentioned would be for the interface between a Caplocks side drum and the barrel.
See my comment below for tightening the nipples.
Someone asked about tightening the breech plug? IMO, nothing has to be as tight as a TC or Lyman Breechplug. I suspect they do that for legal reasons? Of course, the breechplug threads are usually 1/2 inch or larger and can take a LOT of torque.
IMO, a Breechplug should be torqued to around 25-35 Foot Pounds. I am, of course, speaking of sidelock guns, not In-Lines.
With In-Lines, follow the manufacturers recommendations, and don't forget to grease the threads well.
As for the CVA Hank mentioned, the CVA with the two piece stock has never been known for being a high quality gun.
I am not saying they are no good. In fact, they can provide a lot of enjoyment for a real low price, but things like the nipple threads in the drum are not always up to what we in the USA would consider as acceptable for high stressed applications.
In making some of these threads, they IMO, used oversize drills (to speed production?). When they tap (thread) the hole, the threads formed are not "full threads". In other words, they do not have all of the material they should have for strength.
If you own one of these guns, do not remove the side drum and
do not overtighten the nipple . Snug will do.