Here is my ACH Kevlar IIIA ballistic helmet that I bought from the classifieds here and have been upgrading for two years now. It started as a original gray helmet with UCP helmet cover and original pads, straps and NVG mount.
For the last two years I have been buying parts for it as they came up on ebay and different sites.
Build List:
Issue ACH helmet cover(multicam)
Issue ACH NVG mount(Tan)
Norotos USGI NVG rhino mount
Emdom helmet retention strap(Multicam)
Revision desert locust goggles with thermal lense tinted(Multicam)
Surefire helmet light (HL1_C_TN)
Ops Core ACH helmet straps
Oregon Aero helmet pads(to fit MSA Sordin avenger hearing protection)