I've just found out that Happymodel uploaded the STP files for
Sailfly-X canopy and battery holder, you can download it from here:
http://www.happymodel.cn/index.php/2019/05/15/stp-files-of-canopy-and-battery-holder-for-sailfly-x/
Or if you just want to print them, I've converted them to STL :)
30_Degree_Canopy_for_Sailfly-X.stl | 31.6MB | |
40_Degree_Canopy_for_Sailfly-X.stl | 27.6MB | |
Battery_holder_for_Sailfly-X.stl | 77.8KB |