The brass tube should be one piece, when I replaced it on my 1973 20cc, it was about 3" long. That was from the bottom corner of the fish box to where it penetrated thru the hull.
I'm assuming your boat is a 20', but what year?
I'll post some pics when I get home this weekend. Or, we can call on No Bones to come thru with some pics
BTW Ken, my schedule is looking better for Long Point
Lloyd