Metadata in composite images

I've created an image in PS that is from 2 files, one taken with camera S is the primary subject and one taken with camera N that was merely for a sky.  Upon saving - and importing to my LR catalog, the metadata shows the composite is from camera N and dated 9 years ago when the intent was to be able to find the image based on camera S and the current date - like 3 months ago.  I was able to modify the capture date in LR metadata, but I haven't been able to modify the camera used metadata.  How does LR and PS deal with composite images from 2 different cameras AND dates years apart?  Is there a way to change the metadata to reflect the primary camera used?