I've never myself actually seen the plated metal ones in 49-50 KF products as KWZ states, but I will take everyone's word for it that they do exist, and likely, were a sensible replace for the plastic at the time. My 49 Kaiser has the plastic ones, and I have always wondered what I would do if the plastic failed due to age...
To be fair, The only '49s I owned were a Virginian and a Manhattan, so if the Kaiser Specials and standard Frazers had plastic, I will take everyones' word for it.
