It sounds like adding a proper traveler is not as cut and dry a proposition as I first thought. I would think that there should
be adequate strength on the deck aft of the coaming but you will need to do a few things. First of all the top of the traveler should be raised to the height of the coaming in order to be have a proper angle to easily adjust control lines
. While teak would seem like the logical material, there is a forward thrust to the mainsheet and control lines
that would require complex engineering in wood. I would suggest having a small welded aluminum structure built. This structure would need to have a small beam upon which to mount the traveler track and would need to have perhaps 4 legs that were perhaps trapezoidal in shape and with stiffeners arranged to take both fore and aft and athwartship loadings. These legs should be thru-bolted thru the deck probably with 2 to 3, 5/16" diameter bolts per leg. I believe that Irwin cored their decks and so you will need to half drill into the core, ream and clean out the core for an
area perhaps an 1" to 1 1/2" in diameter and then fill with thickened epoxy
. Below deck you will want to use barrel bolts, fender
washers and backing plates. The backing plates should probably be pretty thick (3/19" or 1/4" aluminum) and should span between each pair of fore and aft bolts.
As to the benefit of adding a new traveler, certainly having better sail controls will make the boat more comfortable in heavier air and will reduce weather helm. That said, the C&C was a comparably light weight boat, with comparably little wetted surface and a reasonably generous sail plan. So small changes in sail handling hardware can make a big performance difference. That is not the case with the Irwin 37 which is a heavy boat, with a lot of wetted surface and small sail plan. While there will be some advantage to having a useable traveler, and the current traveler design is a little dangerous to use, I am not sure that changing the traveler will have the amount of benefit that you may be anticipating.