I thought I would post this as a general FYI for those purchasing the APS metal gearbox from Azeal - as I had some trials fitting it to my full metal receiver (from Wish.com)
The main thing that is required is the spacer (6mm) between the Gen 9 T-Piece and the grearbox. There was nothing to say this is required and only from looking at a post from @Maystro did I figure it out. I used a Whiteboard Marker to solve the problem and it fit perfectly!
The other item was having to shorten the front of the T-Piece to fit the Receiver and had to dremmel the receiver to fit the Gen 9 T-Peice.
The only other fix was the fire select on the gearbox needed minor alteration to alow the fire select on the receiver to rotate correctly.
I also had to remove the blowback device as the charging handle wouldn’t fit as well.
One question I have for people is -what the hell to do with the wiring loom?? (pic below)