Could this be a prototype for the T.J.Harrington Gat?

[Epicyclic]

Just a thought, but from the grip shape, there is a nod to an earlier pre war "Brittania" air pistol retailed by Frank Clarke. Don't suppose you have one to disassemble, to see if there is any similarities in the trigger mechanism, perhaps the use of the vee spring ? Cheaper non precision air pistols, maybe because they were generally sold for children and needed to look as exciting as possible, often seem to loosely follow real pistol appearance, in their design. By the later 1930's, the more modern semi automatic cartridge pistol designs had flat bottomed grips, the rounded bird head style grips had gone out of fashion. It would have been a fair bit of extra work making those rounded grips on your pistol, if they weren't intended on the final design.

Interesting thoughts about the Frank Clarke 'Britannia' Morgan and yes, I'm with you on all the curvey stuff.
There are two slab sides to fashion and the internal laminate spacer- though this appears not so accurately formed,- not forgetting the work on the grip plates. All pretty well thought out and proportioned after the internal mechanism was 'created'. Or possibly 'in tandem'...keep reading.
I believe that the extra work in the styling gives us the best clues as to its provenance, as opposed to the examination of the principles of operation.
I contest your assertion that the creator had no wish to be proud of his (or her!) work, John.

Like Silva (above), I see the 'extra' here which grows on me the more I look and let my thoughts turn.

The pop-out is going to work, what could be under scrutiny is the matter of proportion- it has to fit in the hand!- and probably a small one.
I return to my contention that what could be a subject of experiment is the trigger position and associated linkage and my question about the efficacy of this carefully and rigidly designed jig to provide scope for investigative flexibility, remains.
When designing guns, you have to 'split' your thought processes, designing from the 'inside -out' and the 'outside-in'. I refer to the harmonising of mechanical requirements and human ergonomics. It has to both work and fit in other words.
You can't let one 'run away' without bearing the other in mind and a large amout of fluid thinking is needed so to not 'go down rabbit holes'. More the case with pistol design than long arms as it has to A.fit in the hand and B. not be too dimensionally small inside so as to create component weaknesses.
John Bowkett used to make his prototypes in Pistol form then scale them up to Long-arm size for this very reason. You can go one way, but not the other.
( here I pause to express wonder and admiration for esteemed mechanical wristwatch and clock designers!)

Returning to the subject and with reference to the above, I think there is evidence of cohesive thought in the execution.
Design of internals harmonising with ergonomic requirement and topped off with some undoubted flourishes of form.
The latter is always a bonus to the designer as the hard work is done, it works and fits and lastly allows scope for a few individualising touches which grant its appearance defining characteristics by which it becomes popularly identified and cherished.

I see signs of that here.

The art is to be able to visualise much or even all of this from the start, think of David from a block of marble.
One and the same thing in many ways. What is under discussion here is directly related in artistry even in the finest examples of the art being superior in having measurable function in addition to aesthetic form.