Looking at your pic my guess is the 53, or 21" frame size is going to be a bit on the small size. On a touring bike like the 520 it is better to err on the large size if you are between two sizes. The reason is that effectively raises the bar to seat relationship, putting you more upright.

I happen to have a 1995 21" 520 and it is slightly small for me because for 5'9" I have longer legs/shorter torso. As a result, the bars are at or below seat height which is a bummer on tour. Yes there are things I can do about it but I have another touring bike and I now keep it at my parents for general use and day rides which presents no problems.

The net of all this rambling is: consider the larger size or a different bike.