London-based publishers Raphael Tuck & Sons started producing picture postcards in 1900 and continued for more than half a century. The Tuck company lost a lot of its original material during World War 2 and merged with other companies in 1959.
The following are Rhyl examples of Tuck cards - Foryd harbour, the pier, Open Air Bathing Pool ('The Baths') and sandhills opposite East Parade. The photos would have been taken circa 1950.
From the same source and of a similar date are these shots of Palin's Ideal Holiday Camp, Towyn near Abergele:
The camp certainly looks a lot different now and has been renamed Palin's Holiday Park:
http://www.palinsholidaypark.co.uk/
--