Finally got it. Kind of a pain in the @$$, but it will do. Don’t know why the guides won’t just snap to center anymore. But, in case anyone else can’t figure it out, select the entire layer then click the align vertical centers and align horizontal centers buttons. They aren’t selectable any other way. Doesn’t seem too obvious…
Unless, of course, someone has a better way of getting things centered. I’d be interested in hearing it.
TC