Hi;
The closest match I have come to use is the BUFF that was used by the U.S. Coast Guard in the forties and fifties. It's changed now. But, it is still easy enough to make. One empty bottle( Testors MM.Size.) Four drops( Medium ) Chrome Yellow (Not Chromate). One third of a bottle of Light Tan.
Oh! these are all flat colors. Shake well and then let sit for about half an hour and shake and stir again. Now, Here's where you'll think I am nuts. Two large drops of Dark Grey! Again Mix well. Last Color, Leaving room at the top Add Flat White. Now really mix well. The color will be kind of blah! Add Chrome yellow till it looks right in reflected light. Then Paint to your hearts content.
I use this so much on Commercial ships I make a lot! Usually about Six or Eight bottles a year. I also use it in Model Car and Truck interiors. In them it takes the place of what the dealers call " Buckskin". P.S. you can also use ONE drop ( Medium ) of Insignia(Flat)RED to turn it to The " Cordoba Leather" Ricardo Mantalban touted in the Chrysler Cordoba ads.