Some shots below of an old Mk III with a proper PH 16M aboard, and various PH eyepieces.
In my humble opinion, the PH 1 series is the best small sporting peep sight ever made. I’d urge you to hold out for this sight, as opposed to bodging up a PH 16 “no suffix,” which someone out there needs for his rimfire!
Fixed-opening eyepiece:
Sight flipped open - so you can use the open sights!
PH 59 “Midget:”
PH 60, this is the eyepiece usually seen with on the Supertarget’s PH 17M sight:
PH “Iris” leaf-type eyepiece, and gorgeous PH 72 eye shade: