The Royal wedding is now just 18 days away, and the shops are awash with all sorts of mementoes and memorabilia to commemorate the big day. Royal wedding memorabilia has a big place in my heart – in 1981, as a little girl, I  had a Diana doll, flag, mug, Penguin book and kept every newspaper pullout I could find. Unfortunately, I didn’t keep any of this, as is often the case with these sorts of, if we’re being honest, quite tacky, souvenir. So, I’ve decided to compile a guide to some of the more tasteful Royal souvenirs of the big day. Who knows, these may be things that you…