They are called door buttons......I had only seen the Perko ones before but now I just searched and found some SS from boatfix.com They are actually cheaper.
http://www.boatfix.com/shop3/store/l...ch=door+button
They make them with and without a spring. Without a spring you have to find the right hardware to attach the black plastic part.
Here's the thread:
http://wellcraftv20.com/community/sh...t=door+buttons