To add on toe Koishi's comment, they also had some Eternal Silence models were also used as stand ins.

to explain to you why its the halo rifle, the tf2 invasion everyone knows was literally cobbled together out of the very little that leaked and alot of stand-ins were used by the community such as the battle rifle from halo ported to the source engine (likely from an early hl2 mod or gmod mod).

This is actually pretty good!
Only suggestion I'd make is to move this to either the Others category or a completely custom category.

actually pretty cool swep i like it