[Proj] cs2cs latlong-GB

[Francesco Mirabella]

Hi to all,
I am a newbie on this list, I am triyng to project some lat-long points
(international ellipsoid on
rome40 datum)( 12.17183333  43.55000000) to Gauss-Boaga Projection
(tmerc on
+international ellipsoid on rome40). I use:

 cs2cs -E +proj=latlong +ellps=intl
 ++towgs84=-104.1,-49.1,-9.9,0.971,-2.917,0.714,-11.68 +to +proj=tmerc
 +lon_0=15
 ++k=0.9996 +x_0=2520000 +ellps=intl
  +towgs84=-104.1,-49.1,-9.9,0.971,-2.917,0.714,-11.68  -v -f %.6f

  I have reprojected the values to GB with grass in order to test the
  result (the
  +result shold be: 2291529.04882672   4825875.89322372 according to
  grass)


  But I get wrong values, especially on latitude (2205154.728842
  5838292.243164)

  can someone help??

cheers,
Francesco