Nice find in great condition.
There were 3 similarly framed models in the '39 catalogues.
The image from the catalogue you posted on the previous page is not quite what you have, the frame is noticeably different at the top head lug, although your example does have that models chainguard.
This of course could be an export market model which could explain the discrepancies. Hercules were the largest bicycle exporters of the time from the UK, and the catalogue image here is from the domestic market.
Here are the two models with your frame lugs.....
View attachment 1571489
View attachment 1571490
... with the previously posted image at the bottom for comparison.
That top headlug design was used also by Rudge and Raleigh and probably several others from the 1900's up to definitely the late 50's.
Your example also looks like it has had the fork replaced by a 'Raleigh' fork at some point in its history, those distinctive dimples on the fork crown are a bit of a giveway.
That might explain why the front mudguard looks a little misaligned in its curvature in relation to the wheel.
That being said, it won't detract from the riding experience, and it's still a great looking bicycle.
(Images from V-CC library).