Late WW2 / Cold War RAC Tanker's Helmet Mark II with Quick Release Chinstrap

Royal Armoured Corps HSRAC tankers helmet Mark II pattern as manufactured from circa March 1945 with the 'lift the dot' system removable liner and the Mark III quick release pattern chin strap. The only marking I can find is a stamp to the inner shell of the helmet 'F09'. I have seen this marking on another helmet. Despite looking hard internally at the liner and strap I can see no other code, date or maker's mark. It retains its original sand textured dark olive drab paint finish and also the RAC hand painted triangle of red and yellow to one side, which appears to be contemporary and not added later. One small dent to shell, slight veneer of rust to inner surface of shell otherwise in good original condition including the liner, the rubber cross and chinstrap, which is still functional and a clever design. A couple of spurious and small white paint marks to outer shell. Scarce.Please note I will only post this item to a UK address on account size and weight. Display head is not included.K53