I installed a 5300 too.
I bought it from ebay, it’s an engineering sample. It works perfectly fine, so you can order one of those. It came with three antennas.
I decided to try and put the third antenna behind the screen. It is indeed a lot of work. I had difficulties lifting the nc10 open and wiring the antenna properly requires an awful lot of patience. I put it right next to the web-cam, between the other two.
In the end I lost one small white thingy that covered a screw on the lid. I replaced it with white tape but it’s noticeable…
This thread was very helpful, thx to all that shared their info and pics o/