So three approaches had been suggested on the FB page for model trams for the chrome effect.  They were proper chrome plating, using nickel silver rods or using liquid chrome paint.  The first one sounded as if it would be time consuming so I went for options two and three.  The liquid chrome paint arrived first and this was the result.  I was actually quite pleased with this and when the nickel silver rods arrived, I decided to go with the liquid chrome paint.  I am using Molotow Liquid chrome and bought the 30ml refill bottle and simply dripped out some of the paint and then used a brush.  It's really designed as a refill for liquid chrome pens but heh.  Note one drop seems to go a long way. Thanks to Mike Wilson for suggesting the paint.