ETA "Etachron regulator" need input

[hamx15]

Hi all....
A thread entitled "Help with an ETA 2842" ....... link
Help with an ETA 2842

Had great input,and was loaded with very good info,that I myself also wanted to know about....
Not the movement ETA 2842,..... but about the (Etachron regulator).

In reading the post it went into one specific area,adding comments about the use of shellac,as retaining hairsprings.

I posted a photo that was added by "lysanderxiii"....showing a standard overhead view of the balance wheel area.. in a 2824.2 movement...

I would like more explanation of the parts in the photo..

I have marked (A and B).....
Terms like Regulator,Regulator pin,Regulator stud,.... and also and importantly....which of these A or B,would be involved with the use of the
added shellac..????
This is all going toward a question about the "Etachron regulator",
and it's use in both the ETA 7750,and the ETA 2824.2.

I presently have a 7750,in the shop,for a problem with it running very fast...
It was initially cleaned (the hairspring),and had the movement speed down to a gain of 35 sec a day...
I was to take the watch back,for further adjustment..
Within 3 days,the watch was gaining speed and ended up running very fast again,as it was initially.
After getting it back to the watchmaker,he said the hairspring was stuck again...
He wanted me to leave it this time.....
I know for a fact,that his first cleaning (de-oiling the hairspring) was done via a liquid cleaning agent.
This 7750 isn't of a vintage area,but neither is it new.
Manufct date I'd guess to be around.. 8 to 12 years ago.
The photo I sent,is marked as I stated with a A and B,representing two,
studs(if you will) that both have to do with the hairspring retention,and regulating..
My guess is that (B) is to simply hold the very end of the Hairspring in place... I think if shellac was used it would be in this area... ???
Figure (A) would be free floating on the hairspring,and used within the
fine adjustment for timing.....????
Is this correct.... ???
I know my 7750 had been into before I owned it,because this watchmaker,stated that the regulator,had been set to full retard,in an obvious attempt at slowing a fast movement....
Cloud it be ..... that in an attempt,to clean the watch at an earlier,point in life,this shellac has been removed,and now is causing all sorts of inability to control,timing....
The watch runs,and all chrono,functions,seem to work well...
The Hairspring keeps apparently sticking .... causing a fast running condition... Just to mention... The watch has never been seen to wander around as far as movement speed...
By that I mean it hasn't been seen to go from sometimes slow to sometimes fast....
It just steps into a condition thats fast (many mins a day).

I ask these questions,because I also have a Tissot dress watch, 2824.2 .... that is currently running fast at a pace of gaining,about 12 minutes a day.....
If these two movements 2824.2 and 7750,are said to contain this use of shellac as a mainstay functioning arrangement.
I don't think I maybe want to have any jewelers using a liquid oil removing substance,to clean a sticking hairspring.......

At the same time,me being strictly a laymen (learning daily),would be seen to be out of line,questioning a trained watchmaker,as to his approach and technique's.
Maybe running the risk of insulting,and then the refusal to take my piece for work....... !!

All I can say is..... man.... I hope these people know what they are doing....
A person taking a watch in for work,that doesn't have a clue,can have more harm done than good.
And then still having to be told that this watch maker can't help me,and will have to send the watch off for repair........
The unwise owner (consumer) never being the wiser,of any bad that was unintentionally done.
My all told experience within the Swiss watch movement world,totals about 3 years...and that knowledge is mainly accumulated from watch forums....Starting with the purchase of my first,diver model 2824.2 movement..
Of all the words used to state the worldly wherewithal,of the ETA movements especially the 2824.2 and the 7750.
I would have never thought,till now,that something like a shellac ingredient as seemingly frail and problem causing as it can be,would have ever been implemented in these two movements.
At this point.... I'm considering the act of,simply trying to order a new hairspring balance assembly,for the 7750.
Giving up on trying to find a fix for this one running fast...
If I do that,I may as well consider doing the same for the Tissot,2824.2.
I do not even know if these components(balance hairspring assembly) can be had,after market....
......... Shellac......... ???
That really hurts......

At three years into getting more and more familiar with these two movements...Thinking that it's all just a matter of nuts and bolts,and tedious temperament,that makes it all work.....
I now find out that....there is also an obvious degree of shortcut trickery.
The implementing of some ideas,that make for a hard time of repair...
If not totally impossible to repair.....
Built with the idea of (not meant to repair)...
The costs incurred to replace the balance/hairspring,probably wouldn't be too much over the costs,of just adding a totally new movement...
Not to mention,actually easier on the watchmaker.....
Neither being a backyard mechanic undertaking,but replacing the entire movement,probably is simpler,as far as possible accidents occurring.
Hey.....it's just my thoughts....
Of which..I've seldom ever been paid for........
Any input on the A and B areas of the photo,and possible,explanations/comments to questions........much appreciated.
Did this get long,or what???? Sorry....