It's an S7. The S7 was made between 1946-1948, they were available in any shade of black you liked! The S7Deluxe was produced from 1949-1956 as was the S8.
All the S7Deluxe's were Mist Green, quite similar to look at when comparing to the S7, although virtually every part is different! The S8's as you say Littleade slightly 'lither' and more sporty, smaller wheels and front forks, and an Art Deco alluminium silencer. They were available in Black or Polychromatic Grey...