Model A windshield question

I've seen a few '29 Roadsters that look they have '30-'31 windshield stanchions (Jon Fisher's '29, Burbank Choppers). Anyone know for sure if that's what is on his car? And how much work is the install? Thanks guys

 

They are aftermarket "folding" or "orchard" posts, they used to made of brass/bronze and you can still purchase reproduction examples. There is a guy whom sells them in the classifieds I believe his name is John Lee Williamson?