Published US M1 helmet with rare first pattern St. Clair liner named Doyle

Superb US M1 helmet with the rare first pattern St. Clair helmet liner in near mint condition. The rare type first pattern St. Clair liner of this helmet is featured in a book which I can highly recommend;  M-1 Helmet, Pieter Oosterman, 2007 (pages 146 and 148-149 of the 2007 Limited Edition and pages 154 and 156-157 of the 2010 Schiffer Edition). The liner is a textbook example with full rayon suspension and square washers. The shell is a textbook M1 McCord fixed bale example with early cast raised brass buckle. The shell is marked 218A. The helmet is a very nice example that would be very hard to upgrade. Surely one of the rarest liners to find, especially in this condition!