Randall:
I would have to say you might be a 52cm with that bike. However, if you went to another bike you might be a 54cm. I would say in a perfect world and your leg length is even with your upper torso length then you would be a 54cm with a (top tube c-c 54cm). However with the measurement you have give me the 52cm bike has a c-c 53 and this should be idea for you. Going with a bike with too long of a top tube will put stress on your back and shoulders. However, without seeing you it is very hard to determine. If you with the 52cm make sure to try a 120 stem, Make sure the seat post is a zero offset, a negative offset seat post can give a false top tube length. Which put your hip behind the crank axis instead of aligned with the crank axis. I believe that top tube with a 110-120 stem would work. Just like the last guy said ride the smaller bike. Send me an email if you have any more questions. I professionally fit cyclist and triathletes and I am currently writing a book on the Optimal Bike Fit.
Good luck,