If it is a B5200E the E would suggest that it is a 2wd model which means you can use a wider range of wheel and tire sizes because you do not need to have an exact match for height, You are going to need to measure the lug bolt pattern and center hole diameter and look for wheels that have the dimensions that match your tractor, Once you have determined which wheel will fit your application then you can select a tire to fit the wheel in the appropriate width/height/tread design.
You can search a variety of different sources for wheels from Farm implement wheel suppliers to golf cart wheels to trailer wheels, Your machine weight is considerably low for a tractor so the wheel/tire load rating also gives you greater flexibility when searching for a replacement wheel/tire combination.