Complex sentence: Three aircraft were constructed, G-EBFK, G-EBGR and G-EBGS and the regular service between Southampton and Guernsey began on 25 September 1923 (the planned service to France was never implemented).
Split into simpler sentences: Three aircraft were constructed, G-EBFK, G-EBGR and G-EBGS. The began a regular service between Southampton and Guernsey on 25 September 1923 (the planned service to France was never implemented).