Great collection of photos!
Markings on Japanese Arisaka Rifles and Bayonets of World War II
Here is an excellent site with great links.
surplus rifle .com
Arisaka rifle disassembly/reassembly
How to Remove Front Sight on T99
On the right side of the sight even with the top of the barrel sand a spot till you see the outline of the pin that holds the sight on. Lay the left side of be sight on a metal object with a 1/4" or so hole in it. You will need someone to help you. Us a flat face punch about 1/8" in diameter - place over the pin and hit real hard with a hammer. The pin in tapered and once moved a smaller punch will drive it through. Now place the sight in a padded vise and pull and twist on the rifle and it will come off. Do not hit or hammer to get it off. Reverse the process to put it back on. riceone.