Now I am very confused about GWS EDF-55. What is net style, what is old style? I have seen at least three versions:
1 - with orange rotor and metal hub pressed into the plastic. Two set screws attaching it to the motor shaft
2 - With black rotor and metal round hub but screwed to the plastic rotor from the front. Exactly like the one on Guanli, but instead of press fit it has two set screws to attached the hub to motor shaft
3 - The same as 2 but the hub is D-shape and the rotor has D-shape hole (not the round one).

So Simply because I did not know what I need to buy, I made the shaft adapter myself. It is exactly like the type 2 - I did not have set screws laying around, so I used some 2-56 laying around. I will replace them with 2-56 set screws. Actually I made three of them because the first one was all done, when I screwed up the shaft hole. I drilled exactly 2mm hole, and I found it was way too lose. Then i measured the engine shaft and it was 1.97mm diameter.

Now I have some pictures to show.

1. How the motor is mounted after I removed the fan rotor
2. This is the original adapter. It is press fit. I tried to take it out - did not work. I heated it wit the torch to the melting point and it still did not want get loose. I gave up. No way to reuse this part. If you want to upgrade to brushless buy set of 55mm rotors with corresponding hub.
3. This is my hub. you see the engine I turned to 23.85mm dia, so it fits standard GWS EDF.
4,5. The engine mounted in GWS EDF-55. You can see that the engine I got is not the same I ordered. But it does the job, so I will not complain. Replacing one unknown brand with another does not make a difference to me