I just installed a new meprolite tritium front sight on my m66. It's the same hight as the original one so POA/poi should be the same. The problem is that the notch in the rear sight cuts the front dot in half, it's not deep enough. I can't just file the old notch because it would hit the base.
Eta. Well, I used a chainsaw file and filed into the elevation screw and base. It's actually a pretty nice sight picture now.
A slightly wider u notch. My favorite.