Great set of TR's and some lovely photos.
I had seen pics of this when I was looking at routes but it was to the right of where we descended so we didn't see it. Maybe next time!
Shame you missed the Grey Man, Mrs BWW was thrilled when we found it because she thought is would be a bit of an anti-climax and I was worried that I had built it up to be more than it should be. We hit it bang on the nose because we planned to return to Loch Trool along the Rig of Loch Enoch after climbing the Merrick. We followed the ridge crest of Redstone Rig pretty much as you did but took a fairly low start too slant off to catch the best line for the ridge. Your route could not have been very far away.
I hope you have another chance there, perhaps you will catch the Marsh Orchids a bit earlier in the year and miss the midges.