Isn't that a 50hz tv? You can't upgrade 50hz tvs to progressive scan although it should produce its best pictures with a interlace component feed. The sets still capable of a better image than most 100hz high scanning interlace rear projection sets and possibly even some progressive rear projection sets too.
I'm referring to the set being a normal 50hz scanning set not a 100hz set with a 50hz progressive option. Good progressive images normally start at about 75hz refresh rate on most sets anyway. Perhaps my memory isn't serving me well but I seem to remember 50hz progressive modes are pretty flickery and 100hz interlace mode is preferable normally as you have a screen update twice as fast even if its only displaying half as much detail at a time.
I have to be honest I've never seen 50hz Progressive scan in operation. All the sets I've ever seen have been 75hz or more. A 57" tv with a 50hz scan rate! Is it not flickery at all? When you get high contrast text on display does it flicker?