Lid for Barrel (East Bierley BD11)

I have found a fly tipped barrel so I am just in need of a lid. I don't know what capacity it is or diameter. It is misshapened and 17" to just over 20" dia. with variations between. I originally requested barrel and lid but as stated I found this one fly tipped. I want to fill it with water and use as a garden roller before converting to a water butt. So an original lid would be ideal.