Yes the sandman fuel filler cap is not the same as the chrome lockable unit, it is a colour coded plastic cap and does not lock, it sits flush with the bodywork (well except the handle section). It is my understanding (could be wrong) that these caps were only fitted to sandman vehicles???

some links to some pics for those who dont know what we're on about:
orange van
yellow van
white van

if the caps are generic does anyone have one lying about??