Vintage Aurora 'button filler' fountain pen Platiridio nib

I purchased this pen at a local estate sale here in Orlando, Florida
and I am having difficulty finding more detailed information
about it. I believe it may be of Italian manufacture from the
1930's - 1940's.
The reason that I believe such is because it has an Aurora
'Platiridio' nib. There is a stamp on the ring on the top of the cap
but I can not make out exactly what it is. I want to think that
it is 925, 900 or 800 but I honestly don't know. I am hoping that the
pen is sterling silver but somehow I don't believe that it is.

Perhaps there is someone that has some more information about
this Italian made button filler fountain pen.
I certainly appreciate this website & venue for being able to post
this pen.

Many thanks to the Collector's Weekly website.
Regards,
Perry