The instant Punk died it became a retro fashion statement. How many people do you see wearing Misfits, Sex Pistols or Ramones shirts that weren't even alive when the bands were together.
If the pants are too tight then cut down the legs and sew a strip of material in to extend the width of the leg, if the waist is to small it too can be extended by cutting and sewing an extension on. To darken the thread try a mixture of blood, sweat, dirt & booze. It's easy to spot the difference between thread that's been naturally darkened and thread that someone attempted to darken in, and it creates an easy way to spot an oogle. But then again it's not hard to spot an oogle anyways.