To sort the liner heights you will need to get the block machined - Stu can do that for you (assuming he has the time).
There are other ways, but given Stu has experience of doing it and is local, I cannot see why you wouldn't take the block to him given that the block is not in the car at present.
DVA recommends hand peening the fire rings prior to skimming - this helps to compress the material around the fire rings to avoid exposing the holes. Now I have no personal experience of whether or not this works and how hard it is to do properly - the skill is obviously in knowing how big a hammer to use and how hard to swing it (i.e., don't let McKean do it
).
If you haven't already skimmed a lot off the head, you can still have a pop at the peening ... even with a lot skimmed off it, there are shims available.
The combination of peening and the MLS shim _might_ get you to a workable engine.
Neil's old S1 had terrible HGF problems which weren't cured by the shim, but the head survived to be fitted to another engine and worked just fine - the liner heights must have been the issue on his car, anyway.
Cheers,
Robin
(I didn't know it was porous) and need to know my options, can it be repaired easily and cheaply? if so how and where? Stu pollock skmmed it as there was a mark on one of the fire ring and that showed up 3 porous marks on different fire rings, all on the same side. I don't think my liner heights are good enough to use the mls head gasket. 
