#4932038
This one actually was Egon's pack.
All the identifying markers In the video pointed out as the one Harold Ramis wore are correct and can be screen matched to the one that Egon is wearing.
If you Google Marshal Arts proton pack you can also see images of it from 84 before it's refit for GB2.

The pack in the reference section under Sony lobby is the one that anovos erroneously claimed was the Spengler pack, Harold Ramis never once wore it on screen although Bill Murray and Ernie Hudson did in a few scenes.

This is the fifth hero pack, referred to as the Super Hero as it features some addition details compared to the other four hero packs.
It's generally considered to be a prototype for the other hero's and is also the pack that features the thrower with a fully animated bargraph and black painted gun knobs in a closeup shot in the rooftop scene during the heat em up sequence.
Glow in the Dark liked this

    Hey and welcome

    My Little Pony/Ghostbusters crossover done by my d[…]

    Great work identifying the RS Temperature Control […]

    I read Back in Town #1. Spoilers : Hate to b[…]