Sorry but, technically, this would be a copyright due to the author - that is to say the photographer - on the basis of a term of his/her life plus 70 years. In practice, I would guess that this counts as an “orphan work”. This is a very, very messy area legally. I understand that my former colleagues in the EU copyright community are trying to produce a Directive to clarify this matter at the moment. Good luck with that. Alternatively, it might be judged to be in the public domain as a product of what is regarded as the “illegal” Nazi regime. Very hard to say. Best of luck in sorting this out, JR.
One of the many problems with copyright is that different jurisdictions have different laws and are not all parties to the same international copyright conventions, so what is permissible in one jurisdiction might not be in another.
In Australia photographs taken before 1955 are exempt from copyright. Don’t know if this reflects an international agreement and, even if it does, what other nations have subscribed to it.
Interesting added possible complexity on the photo above is that it appears to have been hand retouched, i.e. coloured in by hand after being printed from the negative. This was common in the era and even into the 1950s (you should see my implausibly rosy cheeks in an early child photo from that era). On general copyright principles, if the hand retoucher was employed by the photographer the copyright remained with the photographer. However, if the photographer gave the print to a customer (and the photo above is pretty clearly a professional studio photograph) and the customer employed a retoucher, then the retoucher could infringe the photographer’s copyright by altering the photo.
The last paragraph assumes that copyright in the photograph was not assigned by the photographer to the customer, and that the relevant law in the relevant jurisdiction at the relevant time implied that copyright was retained by the photographer.
If copyright was validly assigned anywhere along the chain of possession of the photo, it could be that “The Bill T Collection” is the current owner of the copyright.
Copyright is a complex area of law requiring expert advice in the jurisdiction where the issue arises, and in this case probably with reference to other jurisdictions of historical application.
As JR said, best of luck in sorting this out.