On the Academy/MRC helos in 1/35 the “thingy” (radar) is not preattached.
You’ll have to do some working on the gear (wheels ans stuff). It’s a nice challenge!
The radar dome is an add on on the 1/48 Academy/Minicraft kits of the H-60 series of helo’s.
As far as the water tank and siphon hose assembly go? All I can say, is to try and find some better pics and get you some sheet styrene and styrene tubing and get after it!!
It really shouldn’t be that hard, once you get the measurements and scale them to whatever scale you will be building the bird in.