I did the same route only 24 hours after you. I was also pleasantly surprised by the "boat valley" and it is indeed unexpected - no warning - you just suddenly arrive at it. I signed out at Kilchoan on the Friday afternoon having arrived by bus and then walked to the lighthouse to camp. Then I walked all the way round the top of the northern part of the peninsula in the same way you did. It was a shame you missed out the abandoned village of Plocaig as you can still see the old high street with the abandoned buildings on either side.

The 3-4 miles to Fascadale following the old wooden markers was enjoyable and I took the short cut at Achateny and found a stone stile helpfully located where you get to the road again.

I look forward to reading more!