I'm not too far away from having everything I need to be disconnected before I can pull the engine. Next up was to disconnect it from the exhaust system.
First up, remove the heat shield over the exhaust header. Here is it before:
And the header is now visible:
The Haynes manual suggested that the O2 sensor at the bottom of the exhaust header might be tricky to remove when cold, but it came out easily - here it is hanging out of the hole it screws into.
Now to disconnect the header from the downpipe leading to the catalytic converter. Whoa ... not so fast. As you can see in this picture the connection is held in place by 3 bolts ... but the heads are on the underside of the joint.
After an hour of trying to access those bolts both from above and below I decided I needed to seek some advice. A quick e-mail to the guy who is buying the engine from me confirmed that even someone experienced with pulling Miata engines does not do it this way. Instead the trick is to disconnect the downpipe from the cat and then pull it with the header and engine. It's apparently a bit tricky to squeeze it past the transmission if you are pulling just the engine, but as I am taking both out at the same time that should not be an issue. It's too late to start back on that tonight ... so I'll give it a go tomorrow.