Post-WWII Marbles Stag Horn No. 50 Woodcraft

I inherited this Marbles knife from my father. From the catalogs It appears to be a 1950's era Woodcraft No. 50 (stag horn). He found it NIB while scavenging in a dump (!) In the 1950's. Kept it for years and years, sharpened it a few times but it is basically unused.

The sheath is the original Moose & Goose leather sheath. The box is long gone, alas.

I'd like to preserve this for the future. Any suggestions for care of the blade and especially the stag horn handle?

I have made knives but always in high carbon simple steel and wood handles. The 'high manganese cutlery steel' blade and horn handle are new materials to me.