I converted my old Mato Sturmtiger to El-Mod many moons ago, haven't used it in years due to the traverse being busted (and it has the original Mato 'race spec' gearboxes fitted as well!) but it was built to pass inspection at Danville should the need ever have arisen.
Originally I tried to keep the airsoft mechanism and have the IR mounted below it, but the low mounted tube you can see in the pictures didn't work out so well in testing and so I ripped out the mechanism and put the emitter down the centre instead.
I think one of the DAK crew has a repainted Russian captured version they battle, so I'm not alone in my madness...