Thank you very much for this answer, this already helps me a lot. And thank you also for sharing the eBay link, I can see many similarities between that model and mine.
At the moment I am simply not sure what exactly I have here. The translucent body and the “Pat. pend.” marking made me wonder if it could either be:
an original early production variant,
a restored/repainted model,
or something modified later.
To help with the discussion, I would like to share two additional photos. In the first picture, the body shell can be seen separated from the chassis and the transparent inner window section.
I did not force or break anything apart — the hood/body can actually be removed quite easily. Also interesting to me: there are no visible glue traces around the roof section, which I have seen mentioned for some later variants.
The second image shows the body illuminated from below with a phone light. The red plastic itself appears translucent, which made me question whether the body is painted or actually molded from colored transparent plastic.
Maybe these details are useful for identifying the production period or authenticity more precisely. But at the moment, I put the beetle as "maybe original" in a box ^^.
And here the second picture...