Spent a couple of summers 30+ years ago in Jackson Hole, building a "traditional" log cabin and a subsequent addition.
We used a similar local system of wood chinking, except ours were hand-cut rather than machined. (we were using rough peeled lodgepole pine logs)
We'd scribe a 4" diameter split log filler piece on the outside, using ~4' long strips, toenail it in place with 12D galvanized box nails, Then had a foam guy come in and spray a thin bead in between the logs on the inside to seal everything up; when he was finished we scribed and fitted split wood filler pieces between the logs on the inside, completely covering the foam . Used 12d galvanized finish nails on the inside.
Something like this would give you the look you want and the foam would provide a better seal.
Your cabin was probably a proprietary package produced by a now-defunct manufacturer; little or no chance of finding additional material. You're probably going to have to mill your own if you want an exact match.
Good luck with your project! Post updates when available.
