He looks STOOOOOOOONED

I think you have some resolution issues. The can is clear and the bum is very OOF. I am guessing this was the best homeless guy stock you could find?

jawshoewhah you are sooooooo right! I kew it was a poor photo, blurred it a bit but no great improvement! It just fitted so well. And Toothpick134, living like that I think I'd be stoned too!

Poor guy

Try sharping the beggar's image with the Sharp Mask tool, it may help a bit.

Or, if the beggar image was too small when you pasted it into the bench image, make the bench image smaller.

Just a couple suggestions

Dude, wouldn't the guy in step 2 blend better on the bench ( if flipped?) and maybe some bench adjustment too ? You might have to recreate the bench for him..
If not tempted, here's my crazy idea, you can dress a friend of yours into a beggar take him a pic that would fit the source and blend in. Carefull with the light source Yeah I know, I already said it's crazy :p

Agree with Greymval. You still have time, although it looks like your alternate source would work well if you if you worked with the perspective a bit.

Thanks for the comments.