GEE,
Highlights for th Uniform - Try this .. Do you have any Vallejo Field Grey ? Mix some German Camo Beige with th Field Grey , & those High lights will PoP ! IF you have Oil - Look for a Tube called Unbleached Titanium - Mix that with th Base for your Uniform color & dry brush it on th Tip tops of th Folds, the X-treme wear areas of th Helmet - around th rim & on top , also for th Helmet gently line th rim with some Faded Aluminum, or a Dull Silver !!
Also try th Unbleached Titanium on th Interior of th 251 - dry brushing for Highlights. Put a Dab on a piece of Corrugated Cardboard & let it sit for at least 20 minutes - to leach out th lint seed Oil ( it will Kill th Sheen), then Dry Brush th Interior for Highlights
Just My $.02 Give it a Whirl & see if you Dig it !!