I have about three of the new ones but you don't see the old ones at all. They would have gone out as soon as the slotted flash hider replaced the prong flash hider, the eyes at top would have then been useless...except for retro builds.
I believe these early tools are not common to find. They will not fit the first type prong flash hider only the second type. I seem to recall there was a different tool for the type one prong flash hider - anyone recall ?