What exactly are you thinking of doing? I might be interested but I would need to know how reliable your "invention" is. Failure of a "modified" Ike part is not an option...
i can try to explain it. there would be a short (1-2") port-like piece that would go on the housing. the end of the piece would be opened and would flare out to at least the width of the end of the 16-35. this piece would also have 2-3 more ikelite port clips on it (to replicate the front of a housing). then another piece would be machined to thread onto the dome port (replacing the stock piece that is threaded on there) and attach to the previously mentioned open ended port. so, you would put on the 1st port piece, then attach the lens to the camera, and then snap the dome port on with the larger opening already threaded onto it. only problem is, since you will thread the wider opening onto the dome port, it would only be able to be used for the 16-35 unless you want to keep threading on and off the standard piece back on and off as needed, or made another stepdown ring (then this would have effects on the distance the dome is away from other lenses though. so does that make any sense at all? im going to bed now. maybe ill draw up a sketch of it.