That will be very kind of you to send me the DVDs.
About questions :
1- Note that Garmon is mostly played with 4 fingers not all of the time.So esp.in playing scales we surly must use our thumb exactly like playing accordion.
As you intend to begin playing Garmon,I will prepair and send you photos showing the situations of holding Garmon,your hands,....as soon as possible because they are very important and must be considered to have a comfortable play.
As an experience of mine,I recommend you to try to play it completely with 5 fingers(If you don`t intend to become a professional Garmon player),because playing with 4 fingers although improves fingers fast actions,esp.fingers 3,4&5,affects your accordion 5 finger playing badly.
2- We have two types of installing 1/4 tones for Arabic & Farsi music on Garmon:
a-Putting extra clav.in the empty places between mi&fa and si&do
b-Putting extra air valve for the existing clav. and attaching both of them to the main clav. using especial mechanism.
The white Garmon is from group "a"
About my Hohner, I have used the empty spaces on reed blocks to add 1/4 tone to it so you see just 4 of them. All registers work properly with the new system.As you see they are double storey clav.s the lower one is the standard tune and sliding one is 1/4 tune.
Putting 1/4 tones by using registers will affect workability of accordion i.e. the number of reeds for standard tune will be decreased as well as 1/4 tones.
I myself don`t play 1/4 notes but for their arrangement (On my Hohner) I have got some advices from specialists in order to be able to play in more scales.
1/4 notes can be added to free reed instruments in various ways,especially according to the possibilities of instrument.
I have designed an instrument that you can change every note you want to 1/4 tone or other tones by rotating a botton on grill.
But as it is a very precise and hard work, I was not able to plan to start the work yet.
Please don`t hesitate to ask any other question.