don't know which type of 105 it is
Looks like a hybrid of 1050/1051 (first 105 group with SIS) and 1055/1056 (the next generation, known as 105SC) - I don't think there were STIs until 1055, but the RD and brakes look like 1050/1051, as 1055 brakes were dual pivot.
@gbj_tester started
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Looks like a hybrid of 1050/1051 (first 105 group with SIS) and 1055/1056 (the next generation, known as 105SC) - I don't think there were STIs until 1055, but the RD and brakes look like 1050/1051, as 1055 brakes were dual pivot.