The EZ supra retracts are NOT the same as the GP ones. The GP ones are a cheap copy of the EZ ones, and the plastic retract blocks are incredibly weak. Don't bother with them, as you will just be replacing them on a routine basis. Ask me how I know!
I have a Raiden fighter that went through three of those retracts before I refitted the EZ supra ones. The blocks would crack, even when just taxying.
The servos most likely came out of the same factory, yes.