What comes after all the Wimsey books are done?

I've been working my way through Dorothy L. Sayers' books recently. I'm about 10 pages off the end of Busman's Honeymoon, which means that I'm about to run out of Lord Peter (who I'll miss) and Harriet (who I'll really miss. The more I read about Harriet, the more I like her, even though I know we're supposed to be more attached to Peter).

So what next? Should I try the Paton Walsh fanfic continuation of the saga? Or should I try some Josephine Tey? Or something else altogether?