usually, "one-piece" refers to a combined cylinder and head like the average brushcutter/chainsaw uses. and not many places will touch one of them for various reasons.
theres no real challenge to installing a steel/iron liner, other than machining accurately. bore the cylinder out undersize, heat the cylinder up and drop the cylinder in. simply pressing the sleeve in isnt such a good idea as aluminium expands more than steel when hot. means it will loosen up as the engine is running. which is one of the issues with steel bores cast into aluminium cylinders.
then you have to cut the ports in, and thats usually easier to do while the liner is out and being machined rather than afterwards. so you have to line it up fairly accurately.
but, steel/iron sleeves are virtually bulletproof.
getting a cylinder nikasil replaced is bloody EXPENSIVE but there are kits available for chrome-plating. sadly, not only do you need muriatic/hydrochloric acid, but also hydroflouric acid, you have to be able to work the bare aluminium with ABSOLUTELY NO CONTACT with air, oxygen or oil... not really the type of thing to do at home.
new cylinder, $40 odd. compared to a couple of hundred.... i know which one makes economical sense to me...
