A lobster-tailed helmet

A lobster-tailed helmet, skull formed in one piece with six ridges radiating from the top, tail formed of four plates joined by articulating rivets and leather straps, the lower plate with rolled edge; peak with rolled edge, and struck with marks: 'M' and 'I'; sliding nasal bar with spade shaped terminal struck with 'M', fixed by a turn-screw with flattened head; cheek pieces with central perforations and fixed to leather suspension straps by domed rivets; the top with a small loop fixed through a large washer. 17th Century Hungarian type.