What should I do about the cylinder...nothing was there in the 8 spots when I removed it...should I get some o rings or just leave them empty?
Depends on your head gasket........ I tried to get the parts from Honda that were numbered in that service bulletin, but it proved to be a dead part number. If it has small holes like the first pic then orings won't it.
I got a HG with the bigger holes and fitted viton quad rings. One year, 3000 mi later......no leaks. But I'm not totally comfortable with it as those knock pins are there for a reason... to keep the oring in place.