Ive had mine apart and I "rebuilt" it. I only had 2 orings. Not that thats all that was ever there, Im the third owner of the boat, but thats Ill that was in it when I took it apart and put it all I put back together. It works fine with no leaks. 1 oring in top and 1 in the bottom.
Ill have to let someone else comment on the cable and box as I dont know.
Your port may be different.................. Ron would know best. Pictures would help a great deal also.