Graffiti: Model It or Not?

Back in the 1957 Bob Decker went the entire length of the Northern Division taking pictures of every CV building and facility he could – whether or not there was a train in the picture. 
I didn’t notice something interesting about this shot of the Essex Junction, Vt. water tank until I scanned the slide and looked at it on the big screen. Although whether or not to model graffiti is a question faced by modern era modelers, I didn’t think it was an issue for me – after all, I’m modeling the steam era in northern Vermont – hardly the kind of place and time I expected to see any graffiti, even something as innocuous as this particular example on the base of the water tank.  
And this says “Class of ‘50” – and I know Bob Decker took this photo in 1957, so this graffiti was around for a while. So, the question is, whether to include it on the model of the Essex Junction water tank or not.