When I bought my model 64, one of the first things I wanted to do was to install better sights.
Sadly, it seemed I was not the only one with this desire but no one had documented what was needed.

First a Williams WGRS-54 rear sight installed on the rails on the receiver.
http://www.midwayusa.com/product/121...aluminum-black

And for the front a Williams .250 Front Sight Riser Block and Williams Front Sight .500.
http://www.midwayusa.com/product/682...aluminum-matte
http://www.midwayusa.com/product/170...1-16-gold-bead

My laser bore-sight is showing that I could have used a little shorter of a front sight. But I will reserve judgement for next weekend when I go to the range.

All told it was about $50 in parts to upgrade the sights on my 64.