Re: Happiness is a Clean Bayonet
I'm not sure what the Japanese used to treat wood - but, I'm thinking that, from personal experience, a first coating of thinned (with mineral spirits about 50/50) Tung oil, buffed when dry with 4 ought (OOOO) steel wool, followed by a full strength coat of Tung oil will give you a nice, weather resistant, preservative finish. You can add more coats of Tung oil if you wish - the more you do, the shinier and harder the final finish.
I'm sure there are some military "purists" who may have the actual finish they used.
Jim Hauff ~ H&R Collector In Memory of Bill Goforth and Jim Ritchie