those sleeves are centrifugal spin cast iron, and very brittle if someone plays football with them. There are cylinders available on eBay. I used to live walking distance from L.A. Sleeve, great people, fantastic sleeves. To to the sleeve refit, you will also need to source new sealing O rings, in METRIC sizes to seal the sleeves back into the cylinder block. The sleeves have register flats cut into the top flanges, so when installed, they do not spin/rotate in the block. Chilling the sleeves and heating the block is the way to insert the new sleeves, but, don't forget to LIGHTLY coat the O ring areas on the sleeves with anti-seize.
If you do go the sleeve replacement route, please ask for your old sleeves back. I, for one, would like to know how thick they are in various places, so I can figure out even larger big bore oprions for our engines, and cutting up an old sleeve would sure help.