Some of my ML's are so old their lockplate screws had to be faced off. The wood shrinks after decades! (I don't own many guns made after Winchester's menopause of 1964.)
As I usually, though not every time, dismount the barrel for cleaning,( I am regularly caught by "Mother Williams" cleaning my ML's in her tub!) I can see whether the lockplate needs cleaning. Depending on your guns' design/fit you can tell whether it catches a lot of fouling between the plate and barrel. Hence the value of good fitting of parts to parts and wood? The triggers don't catch much residue, nor dampness. Clean and oil them twice as often as common sense dictates?
BP residue is very, very corrosive, as you know. You wouldn't let your bore go w/o addressing the presence of fouling , would you? No more than you'd hunt in the driving rain with your 30-06 and then just wipe off the outside?
I'm trying not to sound "teacher-ish". I was a "schoolmaster"as well as a gunsmith before I retired. Now, my age and infirmity necessitate lots of medicine so my advice might be "foggy".
I have some archaic tables of the proper torque for various screws in ctg rifles. Most factories can provide them? As overtightening the lockplate screws can put pressure on the barrel they can affect accuracy. (I bet Daryl, who is the best source of stat's in here, I think, can help, here!)Same with overtightening the trigger gd. screws on the ctg guns.
Some brutes might constantly torque down every screw on their guns, with herculeum strength, and shift the fit of trigger/sear. etc. I suppose some of these parts could wear to "polish" then be shifted off to points of contact less appropriate. Shift bbl/lock, too. This may be reducing the argument to absudity?
One rumor about WD-40. Some gun-gossips say it removes all the water and oil and leaves a surface, after evaporation, that is conducive to corrosion and freezing up> I don't know if this is true but it isn't wood-friendly! It might clean the metal extremely well and leave a clean surface for the next corrosive element to attack? Most say great to clean, then oil!
Take it out and burn some powdre. Then dis-assemble and see where the soot and fouling accumulate. Let this be your guide to the frequency of removing the lockplate and triggers. Your reluctance to subject screws to repeated working and torqueing is not a bad thing. It shows you are thoughtful about what you do! With this kind of awarenes you can't go wrong.
Flashguards can protect a cap-gun but a flintlock obviously fouls the side of the barrel. It's hard to get down at the lock/bbl area. Hence they need to be dismounted (bbl)almost every time?
Did this make sense? Everyone else seemed to think you should remove lockplate everytime. I bet they know more than I do!! Better listen to them! :yakyak: