LAKE CITY the cross signifies its Lake city and NOT hungarian, the 63 is year of manufacture it should be corrosive primed the reason for mercuric salt primers is longer shelf life when stored, Ya should always consider all military ammo corrosive and clean accordingly.
the SB could be
Arms Corporation of the Philippines, (formally Squires Bingham Co.) Marikina, Republic of the Philippines
Empresa Nacional Santa Barbara de Industrias Militares SA, Toledo, Spain
Israeli Military Industries, Tel Aviv, Israel
Sellier and Bellot, Schoenbeck/Elbe, Germany
They all use SB for headstamp
if ya can post a couple pics, better description, what kinda case's steel, brass what kind of case finish?