Review wanted - Classic Army CA MP5A3

[mikewaters]

Hello,

I am going to order some upgrade parts with my CA MP5A3 but I dont know about the internals. I'd be grateful if someone who has opened it before can give me some information. I specifically need the following info:
Type of gearbox (v2 or v3)
The spring (m90 or m100)
Are the gears plastic or metal? Is the sector gear half teeth or full teeth? The cylinder, piston head, spring guide, nozzle etc. Which of these are metal and which are not? Other info you see necessary etc.
If you can help, please spare a few minutes of your time, thanks