@Halfastern: Thanks for the tee nut name. Yes, that could work. It's used incorrectly in the piece I've shown (or it's a different thing entirely), but I can do better with a tee nut and proper nut and washer. @Billyclub: Sorry the picture doesn't work for you. It still looks good here, but it must be specific to the environment.
Could someone please tell me the name of the fastener I've pictured below. I'm reworking the vinyl covered panels that cover the gunwales in my runabout. Some of the 25-year old fasteners look like the one I've pictured, while the flanges of others - the parts that grip the wood at the base - have rusted away, making the fastener useless. I'm going to replace the wood and am wondering if I should use this same fastener, or if there is a better option. Thanks for your help.