It was 64 mm (2.520") when it left the factory, Mark. Given the minimal ring gap, it probably isn't much more now - it just didn't live to do much work I suppose.
The crankpin is the main worry at present. I'd linish it with long strips of whatever you use (cloth backed emery, or wet and dry) of about 400 grit. Just pull it back and forth like a shoe-shine rag.
