Hi,
The "cloverleaf" maker's mark belongs to Alexander Sturm of Vienna, a well regarded maker and I believe they still are in business.
Regards, Tom
ps.
There will not be an .800 mark, as Jorg explained, within the mark of the woman's head (Diana), there should be a single letter (indicates city) and a single number, usually 2 or 3 (3 indicates .800 purity)
