Czech S-42: EPSG:28403 - S-42 (Pulkovo 1942 / Gauss-Krüger zone 3)


Transformation towgs: EPSG:1289 - 3 parameters: 26,-121,-78, Accuracy: 3 meters for X and Y axes (whole Czechoslovakia - Czech Republic, Slovak Republic).
Maybe slightly higher accuracy with: +towgs84=26,-121,-79,0.025,0.035,-0.025,1 

Other formats of definition at SpatialReference.org:

Proj.4:

+proj=tmerc +lat_0=0 +lon_0=15 +k=1 +x_0=3500000 +y_0=0 +ellps=krass +towgs84=26,-121,-78 +units=m +no_defs

WKT:

PROJCS["Pulkovo 1942 / Gauss-Kruger zone 3",
    GEOGCS["Pulkovo 1942 Czechoslovakia",
        DATUM["Pulkovo_1942",
            SPHEROID["Krassowsky 1940",6378245,298.3,
                AUTHORITY["EPSG","7024"]],
            TOWGS84[26,-121,-78]],
        PRIMEM["Greenwich",0,
            AUTHORITY["EPSG","8901"]],
        UNIT["degree",0.01745329251994328,
            AUTHORITY["EPSG","9122"]]],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]],
    PROJECTION["Transverse_Mercator"],
    PARAMETER["latitude_of_origin",0],
    PARAMETER["central_meridian",15],
    PARAMETER["scale_factor",1],
    PARAMETER["false_easting",3500000],
    PARAMETER["false_northing",0]]

Comments