Mono anglais? Jun, help! Two images of night scene are modified BSA B31 or B33 (1954-56) B31 is 350cc & B33 is 500, but not sure by these angle. Third is Triumph Tiger T110 (1953-) Replica of Dean's '55 T110.
I've corrected it.
This one has swing arm rear suspension so is no earlier than 1954, the first year of the T110, but this one is a TR6.