Welcome to Coin Talk. The 1970 was minted in Philadelphia and there was only one size date for the P and D cents (The 70-S was the only one with a large and small date). It would be a lot easier to tell if photos were taken from directly overhead of the coin. Notice how the tail of the 9 in the date is pointed downward and the strong LIBERTY on the other 3 coins. IMO they are all large date. Here's a link to check: http://koinpro.tripod.com/Articles/1970S1cSmAndLgDtCompare.htm
