At about the seven and a half minute mark, the developer says, in a video that was posted on June the 2nd of 2016, "over the past few weeks, we've certainly had some awesome assets being built, and these assets we had made from an incredible artist...". Well, if we look up the name of the artist and find his websites, we can see the
exact weapons, unless I am very much mistaken, for sale for $320 for the lot right here:
https://gumroad.com/timbThese weapons were also featured here:
https://www.artstation.com/artist/timbergholz These pics were posted, according to the website, a year ago.
Here's a hint to the developer: just buy the models from the modeller's website for $320 a year before you have him make them for you. Hey presto, time and money saved!