Mica Sonic is Italian. I have attached photos of a pair of hats with better preserved markings. It is possible that in some years Mica Sonic manufacture shifted from UFIP to some other company in some other country. It is also possible that the details of the ink shifted over the years of production by UFIP. See what you make of these markings. You hats might well be earlier then these. Often Italian cymbals have no die stamped trademark and just have ink...which then gets lost over the decades.
[img]http://www.vintagedrumforum.com/attachment.php?attachmentid=131549&d=1594413669[/img]
[img]http://www.vintagedrumforum.com/attachment.php?attachmentid=131550&d=1594413669[/img]
[img]http://www.vintagedrumforum.com/attachment.php?attachmentid=131551&d=1594413669[/img]
[img]http://www.vintagedrumforum.com/attachment.php?attachmentid=131552&d=1594413669[/img]
The overhammering visible on the 3rd image looks like my older (1950s/early 60s) UFIPs with the over hammering.
[img]http://www.vintagedrumforum.com/attachment.php?attachmentid=131553&d=1594414192[/img]
If the 18" is 1950s that would also fit with the 22" A Zildjian which is a mid 50s block stamp (aka Large Stamp 1).
http://black.net.nz/avedis/avedis-gallery.html#large
[img]http://black.net.nz/avedis/images/hb-detail-stamp.jpg[/img]
Does the 18" actually say Mica Sonic on it? I'd be very keen to see any ink or other markings if they are there. One of the things to check with the 18" is the exact diameter of the mounting hole and the exact diameter. If it is unaltered 1950s Italian then the mounting hole should be a bit smaller than the modern standard of 1/2". It might be close to 7/16" but is just as likely to be some metric equivalent. If the hole has been enlarged post factory so it fits on modern stands you might see the telltale signs of that. Of course the same goes for the A Zildjian 22" which may show signs of an enlarged mounting hole. See:
http://black.net.nz/avedis/holes.html
The diameter of the cymbal is most likely to be the metric equivalent of 18" at 45 cm so slightly undersized 18". Of course that doesn't prove Italian origin since several cymbal manufacturing regions (China, Europe, Turkey in particular) are known to produce undersized cymbals.