Thanks for your help so far.
Turns out I bought the bones of a 1921 Touring, not really a machine that you could really classify as a car.
I connected-up the starter and found it wouldn't turn over. So I removed it, disassembled it, and found this...
Maybe not easy to see in the photos, but the insulation is worn through on the commutator wires and the brushes are worn at all sorts of weird angles.
So I've pulled it off the car. I'm going to blank-off the starter hole for now. Or cave-in and buy another starter... I have time to decide.
Then I decided to hand-crank the car. Retard the ignition, pull through and check the coils seemed are buzzing like they should, choke a bit, crank.
Crank. Crank. Crank. Crank. Crank. Crank. Crank. Crank. Nothing.
Starter fluid... Crank. Crank. Crank. Crank. Crank. Nothing.
Pull the plugs - three stuck valves. Two intake, two exhaust.
So this morning I drained the coolant and pulled the head. One valve I can get to move by tapping it down, but the other two are jammed. What a nightmare. I'm away on work for a few days so I'm going to soak the shafts in ATF and see what's up when I get back. In the meantime I've ordered a spring compressor. May add a reamer to the list, too.
One advantage of all this is that I've gone from Zero Model T Mechanical Knowledge to Some Model T Mechanical Knowledge pretty quickly. I'm getting to know this car pretty well now...