Yes, I have a couple all-metal mechanism TKs. My Alpha has some plastic in the auto-feed mechanism itself - I don’t recall if the retainer has plastic.
One interesting note about the all-metal mechanism. It can corrode… badly. Not sure if it is a metal-to-metal interaction or humidity or air oxidizing one of the mechanism metals (likely the spring). However, the one I had with corrosion I was able to clean and it is perfectly functional.
