The early double-row timing chain (29) with the concave side of the thrower (28) facing away from the engine (these and the following images from Leyland Workshop Manuals).
The later single-row chain (6) with the thrower (1) facing towards the engine.
Detail of the thrower showing the 'F' (circled) stamped on the side that faces away from the engine, reputedly on the appropriate side of the earlier thrower as well.
The V8 thrower (14) facing away from the engine, I can't recall if this is stamped with an 'F' or not, the text of the manual doesn't mention it.