I'm not terribly hopeful, but at least I know that if they don't follow it up successfully, it won't be because the idea wasn't in the Playmobil pool of ideas. If I ever see Playmobil in a Museum in the UK, I'll know it was my idea that got it there.
I don't know if the relevent representative is on commission, but that's how things were done when I knew sales reps, and any lead is worth following up if you're on commission.
My concern is that either they don't follow it up, or they decide that if a Museum can't carry a full line, then they can't just have some Roman sets. It takes a bit of vision to see what that one Roman figure in a child's hand might lead to, and I'm not sure the reps have that vision, or even time to think about the bigger picture.