Having stitched these panoramas together I realised that neither of them showed the scene as I had retained it in my memory. What I remembered was storm clouds clearing from distant sunlit snow slopes contrasting with the dark mountainside on which I was standing. The first panorama had the desired contrast in lighting between foreground and background but the summit of Beinn Toaig above Loch Tulla was still obscured by cloud. In the second image the mountains had cleared but the brightly lit but rather boring foreground was dominating.
Although the images were taken about 10 minutes apart and without a tripod, the framing of the two panoramas is essentially the same. I opened both images in Photoshop and dragged the first image over the second as a new layer.
After creating a layer mask I used a soft brush set at between 10% and 20% opacity to paint over the mask with black in the central area of the image where the mountains were obscured by cloud.
Working slowly, and switching the paint colour to white as necessary to restore the top image if too much had been removed, the final image was built up. A final crop and a slight levels adjustment was all that was required to complete the image.