exactly Glum, it ain't pretty but hey ,another 500 hours is another 500 hours..
-torch would be faster cutting than disc on angle grinder, but with the disc the cut is super clean and accurate, it makes the fitting and welding much easier...crank up the 6010/ 6011 rod and let it eat, minimal clean up, where the shoe mates up and on the bottom of the chain
-the cross-section of theses areas is surprisingly small for the size of the chain, good steel !!