This is an original 1974 dated Vietnam M1 combat helmet liner shell. This is used and has been overpainted in a thick layer of shellac.  The inside is very nice.  There is no suspension included with this shell, but this one takes the kind of suspension that slips over the little metal buttons.   Remember these later liners don't work very well with WWII steel pots.  You will need a 60's Vietnam era through 80's steel pot to work well with this.