Go here for many model schematics
https://www.gunpartscorp.com/gun-man...9-rifle-series

Where you will find pictures like this:


Where you will find pictures like this


Or be able to purchase parts like this
https://www.gunpartscorp.com/gun-man...fle-series/99e.


This may not be what your after but it just took me a few seconds to look up model 99s.