My fathers and my old Mini Venom had all metal....with the micro adjustable marks on them. Wonder if yours is an older model? I just bought my fathers for the Reflex Grizzly he just bought, and picked it up on Ebay for $25.
I'm not sure....depends on what is considered "old". In the bow market if it's more that two years then it's "old"
I have had it for a few years. I bought it used so I'm not sure just how old it is. Mine also has the micro adjustment marks on it and it also has the little "T" handles to tighten the windage and elevation on the sight so no allen wrenches are needed (only for the pins). It'a all metal except fot the sight guard that's clear plastic, but seems to be holding up fine.
It's a great sight, it's simple, sturdy and reliable and I don't plan on changing it.