I wouldn't put the original up in the house. If I were you I'd bring to the local printers who have the large sized scanners and have them make a high resolution scan of it. Then you can have the copy up in the house. The non-replaceable original can then be kept where it won't be exposed to light and the environment which will cause the colors to fade.
Our family has a bunch of watercolor paintings that my Grandfather made while serving at Luzon and Guadacanal which are definitely irreplaceable.