You could make it passing in front of an abandonned KV 1 soviet tank. The KV1 is a rather large tank and EEC makes a model of it.
Now, I've got a question for the history buffs : when did the nebelwerfer get into use ? I'm asking because german vehicles were repainted in dark grey in 1943. So if someone tells us that the nebelwerfer didn't come in use before late 43 or 44... then it'll be up to you to see if you don't mind or if you want to repaint.
Also, there's perhaps a bit too much rust on the vehicle. but that's a personal feeling.
Sorry, I'm being a bit picky. That's because you've done a great job and I like the choice of the subject !