Might be an idea to measure the outside diameter of your Lead pipe to get the lengths of insulation of the correct size.
Position split on the underside and use cable ties to secure.
you may as well do the lot (up to the outside stop tap/meter)when you get to it - your water company should do a free lead replacement the connection but do double check
£much?
I was blessed/cursed with lead in my first place. Couldn't get the Water Company to replace the feed, but got an oldschool plumber to joint in copper and I took it from there.
Might be an idea to measure the outside diameter of your Lead pipe to get the lengths of insulation of the correct size.
Position split on the underside and use cable ties to secure.