So, it seems this joint isn't as straight-forward as I'd hoped. Figures. I had a bit of a further look through (some) of the books, and the rarely mentioned Wood Joiner's Handbook by Sam Allen, which has delivered the goods before, has at least mentioned this one - calling it a Housed Carcass Pinning. He sez cut the tenons first - which I'd have assumed was entirely arse backwards - then the housing, then the mortises. Which is 100% more information than many another book has got. It's a handy tome that one, and insanely cheap on the secondhand market - just ignore the endless use of unguarded tablesaurs and you're golden.
Anyway, nothing further to add at the moment - w'shop time is non-existant just now, however much I'd like to be trying fifteen different ways to cut that joint. And no, I really wouldn't. What I'd really like is all these woodworking geniuses (genii?) to branch out a little, stop telling me how to dovetail (I know that - I may not always get it right, but that's through my fault, not a lack of available instruction) and devote a little more DVD space on some hand-cut joinery that hasn't got a 1:8 slope involved. However, no blog post is truly complete without a picture, so let me not deny you.
Just as soon as my interweb connection hauls itself back out of the dark ages, I'll try and get a few other pics on here. Of some chisels. Various. Y'know, just in case anyone wanted to see the differences between, say, one make of chisel and another. Maybe a few comments on one make of chisel. Stuff like that.
But then again, you're probably not really interested.