The Triang R226 SR bogie utility van is fitted as standard with ill fitting window glass that is screen printed with white security bars. I converted my model using 'South Eastern Finecast' flush-glaze windows (SE63). The flush-glaze are embossed and fit snugly into the window recess from the rear. However, they do not carry the security bars so typical of the prototype.
My research into the design of the bars lead me to a preserved van on the Bluebell Railway. The bars are fitted inside and comprise three horizontal and four vertical bars. I created the security bars in Photoshop and printed using an inkjet printer on transparent film, thus creating a printed window glass. The bars are 1 pixel wide. I could not determine the bar colour from available photos so opted for the same colour as the body - green.
Three attempts to assemble bars and windows to the van before finding the best technique that does not result in liquid glue residue 'frosting' the glass. Fortunately, there are sufficient flush-glaze spares supplied in the pack to cover for failures. The solution was to use tape instead of glue, as follows.
Cut out each flush-glaze window from the strip leaving flanges on all four sides. The bars-glass is stuck to the rear flanges of the flush-glaze using strips of double sided tape This now looks like double glazing with the bars sitting back from the front glass. More tape is stuck to the otherside of the flanges and the assembled window offered up to the recess and pressed in place.