When you say "heritage line really" I'm not quite sure whether you're saying it's a model of the 1930s situation or whether it's a model of a "heritage" (what we used to call preserved) railway attempting to recreate the 1930s. if the latter, you would probably expect some more modern standards to be used in deciding what signals to have or where they should be.
If you want a diagram that looks right, it'd be no bad idea to add the trap points... if you don't get an excuse to add them to the model sometime, some rails (old point blades?) in the right place might at least give a visual impression that would help. Stockley would also need a set of traps at the right hand end of the loop, of course, but trapping can just as well be achieved by using a crossover with the "trap" route as a headshunt (of whatever length you like). As the traps would most often be worked by the same lever as the corresponding turnout, there would be no problem with extra levers and complicated numbering on the diagram.
The other thing not shown in your diagrams is facing point locks. If you assume the preservation bods track circuited everything, they would only need the actual bolt apparatus modelled (in the 4-foot between the moving point blades). If an older "feel" was being created there would also be the fouling bars stretching along the inside of one rail back from the toe of the points. If you don't want to model that, you can assume they're on the rail nearest the viewer, but it does make a difference to the rodding run. In the 1930s TCs were considered expensive and they were a bit of a rarity on branch lines (and surprisingly few on some rather more important lines too).
But the main point here is that - with a few exceptions - each FPL would need a separate lever. The Midland Railway was definitely one of the exceptions, making great use of "economical" FPLs (lock, bar and points all worked by the one lever, which should be coloured blue over black), but the GW went with the majority and tended to use separate FPL levers. Point motors have a built-in FPL so if the LH end of Stockley loop were considered too far away for manual working, you'd have a blue-over-black lever with a shortened handle for them. (In that case, that end of the layout would certainly be track circuited. Motor points without TCs were rare. There was only one place I knew that had them - Willesden Brent Sidings from early 1983 onwards - and they proved uncomfortably vulnerable to being moved under a train. That, of course, was goods lines, on which you can get away with quite a lot. The Inspectorate wouldn't allow it on a passenger line.) You probably wouldn't get motors on a branch line in the '30s, unless there had previously been another box at the LH end which was then abolished.
The signalling at Lamorna might want enhancing too. Modern standards on a preserved line would probably require a signal fixed at danger near the buffer stops end of the platform, clear of the fouling point of the run-round crossover. There would be a shunt disc or small arm beneath it to signal the loco past after hooking off but carriages conveying passengers would not be permitted past the signal. (The alternative would be to fit the Xover points with an FPL - platform line only, the loop is considered non-passenger - and to have a disc for the arriving train. A moot point whether, in the locking, that disc should be considered a "facing shunt" that must be cleared before the home can be cleared or whether it acts as the stop signal in normal circumstances, only being cleared for an arriving train when there's a long train & turnover engine.) The 1930s situation would undoubtedly have had a ground frame working the engine release crossover and no signals at all at that end of the layout.
At Stockley, in a preservation-era model it would be most usual to have an advanced starter at the left hand end. It would also be usual, at a location where shunting is likely to be common, to have outer homes (preferably far enough out that the advanced starter in the opposite direction is the clearing point). Outer homes probably wouldn't be provided in the 1930s and possibly not advanced starters either.
That probably complicates things rather than clarifies, I'm afraid. But maybe you can have some fun doodling in spare minutes over lunch (and have a browse through the signalling diagrams on the main site, to see how 'twas really done). And remember there were exceptions and peculiarities that might get you out of trouble. If you look at the lever numbering of St Albans South (1970s layout) it shows what a frame could end up looking like if alterations over the years led to levers becoming spare then being re-used for other functions - the down line signals are arranged pretty conventionally but the up lines are all over the place. All you need is a convincing story!