I'm sorry, but you are wrong. The M189 does have liners and they are only available in Standard size. There used to be a repair size as well, but that has long since been discontinued.

The M186, predecessor to the M189 does not have liners as it is a cast iron block. The M189 is an alloy block.

Here in Australia, there is a couple of people I know that have the knowledge and equipment to install the liners. I can arrange to have it done, but you would have to send the block. Cost is around A$2,500 to do this, so it is not a cheap exercise. I have also recently re-designed a piston suitable for the M186, M189 and M198 engine. It is a forged alloy, with increased compression, better torque, lighter and more efficient than the original. It also used modern piston rings so that replacement is straight forward.