Welcome to AVS Forum.
This discussion topic is actually for one specific Westinghouse model, the LVM-42W2, that was made in 2006-2007. Your questions seem to be about the possible value of the parts in your broken set. I don't think you will get much of a response here about circuit repairs/parts. If you do want to try, though, you should check for a specific topic for the TX-42F970Z model, or start a new topic with the model number in the title (which is very important). This discussion is unusual because it does not have the model number, but when it was started, this was the only 42" Westinghouse model sold, and one of the few 1080p TVs of any brand.
You could also check completed sales on Ebay, searching for "westinghouse" and "lcd" and "power supply", for example. The quick answer, though, is that there is little value in broken flat-panel TV sets or their parts, except maybe for the better brands such as Sony or Samsung.