I eventually finished the Alsonso Arai helmet from his time with McLaren in 2007.  Based on a Minichamps diecast model originally in Damon Hill colours, I converted it by adding a top spoiler, radio connection link and metal connection points for the Hans device straps.   The decals were an absolute nightmare to apply, being very thick and brittle and despite the fact that they were supposed to be 1/8 scale, they did not fit properly so significant amouts of surgery combined with lashings of Microsol was called for!