Being that the tiller is a crucial piece of steerage & a valuable aesthetic item, don't skimp on it. This is where I would contact Catalina Yachts for original equipment replacement. It should cost less the a hundred bucks & is well worth it. Keep the new one varnished properly & it should never rot or delaminate. I would never trust poplar or oak for exterior marine grade application. I saw a fella replace his hatchboards & trim with red oak & they split & cracked apart within a year. Only teak & mahogony last outdoors. That's why they've been trusted for centuries.