Looking for info on this sported Arisaka 99 recently inherited

[MR_David]

Hi. First time here. You probably heard this before, I just inherited a Arisaka 99.
It has been sported and probably has now real market value. I want to know more about it and possibly repair it.
The firing pin is broken near the back end where the trigger holds it and the safety is attached.
It still has the chrysanthemum stamped on the barrel. Until I took a very close-up picture I did not notice that it had something stamped over it.
I made a copy of http://www.radix.net/~bbrown/japanese_markings.html and I still have some question.

I read that the type 99 made late in the war were crap and inferior. Is this one of them?
I'm confused about the serial number stamped on the side. 5888 with a NAGOYA Arsenal stamp.

I have several boxes of ammo and a reload tool set for it also.
I'll have more question later and photos.
Here are some photos

Any input about this gun is welcomed.