Every paintings has it's own unique value. I know someone who painted over another painters painting, and to my opinion that should never be done but by the painter himself.
As for your painting of trees at a stream, always go to a taxator, or art-antiquar to ask about this painting, then you will get the best answer. You might be surprised, and in any way, if you like the painting very much and if it never bores you, it is a well done painting.Always go on an search site also, you can find loads of information there.Every painting is worth the hours and talents it has been given by the painter.
K.Richards can be found on google, even as in Rolling Stones, born in 1943! If he made this painting you could have luck?