Ah! take out the engine to speed up setting valve clearances!
My brother had one; as did my father for a while, in 1947, waiting for his new car to arrive.
Both had wire wheels, rather than the pressed steel disc wheels on the later ones.
I believe that it needed three spanners, unless you put a plate between adjacent cam followers to prevent then from turning while you actually made and locked the adjustment.
At least on the Series E you could access the tappets through a panel in the front whee archl. Didn't stop me dropping a valve collet into the sump! Fortunately, the local dealer had one, so maybe it was not unusual
Taught me to block the drain holes with rag!
Howard