Many Pizza Express outlets are decorated in a way that pays homage to their location, such as a famous umbrella factory or a bicycle factory. In the case of the Muswell Hill Pizza Express, it is William Bernhardt Tegetmeier who is paid homage.
Living near by in Fortis Green, he is noted inside as being the organiser of the first ever pigeon race. He was also a regular correspondent with Charles Darwin about poultry (and possibly other matters; my knowledge of the 19th century Tegetmeier-Darwin correspondence only goes so far).
He was also a founder of the Savage Club, which is now housed in the National Liberal Club and so responsible for the most fearsome sounding door sign in its building.
Speaking of signs…
The Muswell Hill Pizza Express, perched right at the top of the hill, is home to the best toilet sign spotted so far in a Pizza Express:
So that is 40 down, 98 (or thereabouts) to go.