I made a couple of the catwalk pieces, with anchors on the top and bottom. It works pretty darn well, slotting them into the posts below them. It'd be too wobbly without the support pieces, but the support pieces (after some adjustments down to the proper size) seem to work really well.
I had enough time this evening to also kitbash the
tower floor tiles. They're based on a 6" tile, but are 3/4 round and
squared off in the remaining corner - kind of tear drop shaped. This
will allow me to make the exterior of the castle towers rounded, but the
interior will use standard 3" walls to facilitate doors, and abut the
catwalks nicely. The edging is done a-la Hinterland tree bases. I've
done it on other tiles, and it's worked well (and it spared me from
making my own cutfiles!)
It's going to take a couple days to get
all of the catwalk and tower floor pieces assembled, so no photo yet.
After that, I'm probably going to do up a ton of the crenelations,
making the castle look more... well, castley. Hmph. Spell check doesn't
think 'castley' is a word. Maybe it will once it sees the photos...
I'm still thinking about how to do rounded TLX crenelations, but I have some ideas for that too.