Probably stating the obvious here Steven, but having done this myself on some engines, one thing which can be a problem, is the seal between the liner and the head button. I've never had an AA engine, but I would think the surface finish is probably better than most, so less likely to be a problem. If you do need something there to make the seal, you can use thin kitchen foil as a gasket. Stretch it over the bore, use the head button to cut the hole, and trim the outside to match the O/D of the head button......