- Some of us are watching way too much tv. LOL
Any time traveler would just have Leonardo paint 7 Mona Lisa's, and then have the extra six blocked up with bricks to be forgotten for hundreds of years. Then, he's skip over to the 20th Century and steal the 7th Mona Lisa from the Louvre, knowing that he could then sell all seven authentic editions to seven different private art collectors, and each buyer would think they were purchasing the one sole unique Mona, and no one would know the difference since none would brag about their loot.
"The centuries that divide me shall be undone."
- ... On the back of the extra six paintings of the Mona Lisa, the Doctor writes, "THIS IS A FAKE" in felt tip pen and puts them face down. He also writes a quick note to Leonardo, "Dear Leo, sorry to have missed you. Hope you're well. Sorry about the mess on the panels, just paint over them, there's a good chap. see you earlier, love the Doctor." ...