You're right about the stories from tolerances in these engines. There's a strange resistance from some machining companies in believing that the Honda tolerance can possibly be correct!
On forum, it's worth a call to "Trigger" as he really knows what he's doing and has the capabilities to carry it out.
As you mention, the tolerancing for some reason is simple but stubbornly ignored by some working on and experienced with other engines, they are often very persuasive to your detriment.
