Hi Colin
Early cars had gravity-feed to the carb, from a scuttle-mounted tank. Later cars had an AutoVac, a vacuum system, off the inlet manifold, that drew fuel from a rear tank. I thought, at first, you had some form of vacuum fuel supply (the tank on the offside bulkhead) or it was a secondary tank (from the scuttle tank). With a scuttle tank, which you clearly have (= filler on dashboard), then the fuel would be gravity fed. The black tank I assume is for the wipers - a vacuum wiper system was not supplied originally, nor is the windscreen-mounted control correct. You'll see the wipers would not work anyway, as the arm is too long and the blade would be overlapping both the upper and lower panes of glass. The bulkhead equipment and electrics will need completely sorting (e.g. the dynamo wiring is poor). Another observation is that the dashboard is lacking a clock, these were supplied certainly from 1924, so the current wooden dash may have been replaced in the past. The horn, mentioned earlier, would have had a button on a steering wheel spoke (i.e. not the centre).
All the above may appear that I'm being negative, but they are minor really - the car would be a very good, and relatively straightforward restoration project. Of course, we don't know about the engine, that's the unknown at the moment....