The 52 on the side of the bow is how you order the string, tell the man you have a bow marked 52" and he will sell you the proper length string. It will not be 52" but it will be the proper length for a bow measured to 52". You will fine tune the length by twisting the string to shorten or lengthen ( don't untwist a flemish too far ). This adjustment is one of three you will need to make.
A stringer is a very good idea. When you purchase arrows make sure they are spined with a recurve bow in mind. Buy them a few inches long and you will be able to shorten to increase spine if needed. Adjusting tip weight is another approach to adjusting spine weight, keep that in mind when buying arrows, heavier will lower the spine weight. Correct spine is very important when tuning a stick bow, do it wrong and you will be fighting an uphill battle. This is adjustment number two.
When you purchase the string get a few nock points, a bow square, nock point pliers, and some string wax. Adjust the nock point up and down to achieve proper arrow flight. Likely the square will have some instructions, I would start about 3/8 over center myself. This is adjustment three.
Once these three are set the rest of it is you.