My educated guess is P12. The original stem would be a Titan and would have steel bars if it was a factory Tourist. Everything else looks correct for a '68I'm not finding either the P11 or the P12 listed in the '69 catalog, so '68 was probably the last year for these models.
Obviously a lot of parts were changed on your bike, so I think it's going to be impossible to know(without a provenance report from Waterford) whether your's started life as a Tourist model or a Sports model. Both the P11 and the P12 used that crankset.