Just so we're on the same page, you want to place weapons in your game? 
IPL (Item Placement List) only places models in the game, I have seen IPL mods claiming to spawn vehicles & weapons but have yet to find one that actually works.  If there is a mod that accomplishes that, point me to it.  I have placed vending machines, casino games & food carts (all working) w/ IPL mods. 
The GOOD news - 
I have had EXCELLENT luck doing this w/ script mods (SA version 1)!  If interested, I could help you out on that. 
If I did this right, you should have a picture of my work. 
I also stocked a nice National Guard Depot. 
I'm sure you already know about the issues w/ SA version 2.  If not, get the downgrader.