Searcy made a stainless steel plastic stock field grade model several years ago, but no one ordered one so he sold the prototype and was done with it.

One of the Cameroon PHs bought a Krieghoff double and it was essentially destroyed after one season. He had to get all the rust cleaned off and had a teflon-type finish put on the outside. I understand that some of the vintage guns used gold-plated internals to deal with the corrosion issue for surfaces that were hard to reach.

For a 14 day hunt it might be more practical for your friend to do his best to keep the gun oiled but to just plan on getting it reblued and the stock refinished upon his return.