Back in the late 70’s I did a lead plumbing course on the GPO, now BT for repairing the old existing lead covered paper insulated cables. I was told at the time that it was the last course to be run as the lead was being recovered whenever possible. In those days, amongst the old cable jointers there were some superb plumbers, you try plumbing a joint on a cable 4 inches in diameter with a sleeve about 9 inches in dia. & about 3 foot long in a manhole! I was never very good at it & never had sufficient practice & only did one or two small repairs before I moved onto other work. There is very little difference between wiping the solder around nicely & the lead melting into a pool on the floor & the paper catching fire!
EDIT ..... I don’t think I could did it now if I tried ......
I have photos somewhere of the repair section they let into the main at the end of our road a couple of years ago, the repairs were exactly as you said but they installed a copper or bronze earth electrode which must have been 25mm diameter and about a metre long laid horizontally in the trench next to the encapsulated joint box. I did look longingly at it thinking ummmm lathe stock.I watched them do a joint outside our house a few years ago when the power went out and it was nothing like that and the box with pitch was replaced with a plastic sleeve with two part filler.
Perhaps that is why it stayed in the trench long enough to be back filled, big brass clamp on it though.All earth rods at least these days are copper PLATED!
a pair of marigolds and sat on black dustbin bags works well. i cut back and conected a 120 amp tp and neutral armoured out in a carpark down a trench one saturday morning when no one was about to spout health and safetyand the guy wasnt wearing PONCY gloves.....