The top photo looks to my limited knowledge to be a Longstroke A7 ('46?-'50?), bottom photo later Shortstroke model('49->), and if that's the enigine# for it, then A7...I believe as per recent discussion, that the 'S' after 'A7' denotes Star Twin in both cases, as there was Long and Short stroke versions of the ST.
Triumph had external pushrod tubes, so don't think there's one of them...