Hi @andrei.kuznetcov, I conducted a test yesterday. I decided to collect some points on the field yesterday for comparison. My subordinate collected the same points in WGS84 with reachview 2 whilst I collected it with reachview 3. Compared the coordinates of both after converting the wgs84 collected in reachview 2 to the “Ghana national grid”. Coordinates from reachview 3 were off by (approximately 1010ft in the northing values and 89ft in the easting values).
Then I went back to look inside the parameters within the ghana coordinate system and realized you omitted a 7 parameter Bursa Wolfe datum transformation parameters.
Thus, from wgs84 to Ghana Grid { X(m)=199; Y(m)=-32; Z(m)=-322; Rotation X(sec)= 0; Rotation Y(sec)=0; Rotation Z(sec)=0; scale (ppm)=0 }
Or vice versa, from Ghana Grid to WGS84 { X(m)=-199; Y(m)=32; Z(m)=322; Rotation X(sec)= 0; Rotation Y(sec)=0; Rotation Z(sec)=0; scale (ppm)=0 }
I’ve taken the courtesy of copying and pasting the details from the EPSG official web page and highlighted what I’m referring to in “bold” under this write up. Thank you for all the efforts. We’re almost there comrades… 
Anyway, Reachview 3 is superb
PROJCS[“Accra / Ghana National Grid”,
GEOGCS[“Accra”,
DATUM[“Accra”,
SPHEROID[“War Office”,6378300,296,
AUTHORITY[“EPSG”,“7029”]],
TOWGS84[-199,32,322,0,0,0,0],
AUTHORITY[“EPSG”,“6168”]],
PRIMEM[“Greenwich”,0,
AUTHORITY[“EPSG”,“8901”]],
UNIT[“degree”,0.0174532925199433,
AUTHORITY[“EPSG”,“9122”]],
AUTHORITY[“EPSG”,“4168”]],
PROJECTION[“Transverse_Mercator”],
PARAMETER[“latitude_of_origin”,4.666666666666667],
PARAMETER[“central_meridian”,-1],
PARAMETER[“scale_factor”,0.99975],
PARAMETER[“false_easting”,900000],
PARAMETER[“false_northing”,0],
UNIT[“Gold Coast foot”,0.3047997101815088,
AUTHORITY[“EPSG”,“9094”]],
AXIS[“Easting”,EAST],
AXIS[“Northing”,NORTH],
AUTHORITY[“EPSG”,“2136”]]