Hi You will have to do a rewire,first split off the elevation side just two wires to the motor ,this will have to conect to the elevation control on the SLU .next will have to be a bit of a guess the recoil is just like a tamiya from the wriing side,you will have to get the direction of rotaion correct.dont worry about the flash ,you can take it from the lights loom,one of them is a LED flash for main gun.so conect the two wire to the recoil (you may also have to conect the earth conection to the battery)try it with out this first.You may even have to conect both + and - to the battery.

   Im not 100% sure about this so wait for more input some one may have wired one in and knows how to do it.
Standard heng long recoil units work fine ,but these are the only ones I have tried yet,I do have a Hooban unit for the next unit I fit.

    regards pete