Nothing... it is simply an inspectors stamp applied during the assembly process.
It looks like an L, but, it is a one.
Winchester
Winchester Special
Probably Winchester.
The number 1400 refers to the Model number of your Winchester shotgun.
it means turning it on
Winchester Center Fire.
You mean a lever or a trigger? a lever is a doodad and you can build it from the doodad builder in map editor. same with the trigger but the trigger isn't a doodad and you need to set it in the trigger editor
Impossible to answer without knowing which of the dozens of Winchester models and variations you mean.
One shot for each pull of the trigger. The trigger does not cock the hammer.
the trigger of a trap.
Winchester had a lever shot gun with this mdl number, is that the gun you mean?