I like Nerf. I've actually got no less than ten Nerf mods underway (plus modded/accurized Nerf-made Star Wars dart-shooters, and a former SuperSoaker). But. Back when the original trilogy was made, they used a lot of real-world firearms, obscured to one degree on another (some barely at all). A lot of people in the original audience recognized the base weapons, as they were current/recent. These days, between guns being more culturally shunned, and more decades since those specific ones were in common use, they're more recognized as Star Wars weapons than real-world weapons. For instance, most people now recognize the Mauser C96 pistol as "Han's blaster" than something with real-world vintage.
Nerf is different, altogether. Even when people recognize the base firearms the movie weapons were made from, they're still
weapons. When people recognize Nerfs, they're recognized as
toys. That changes reactions a lot. It kills the illusion when a kid sees your blaster and goes "oh, I've got that same Nerf gun at home". To make a Nerf gun acceptable, it needs to no longer look like what it started out as. All logos and raised lettering need to be covered or ground off. The distinctive "digicam" texture needs to be smoothed off. The panel lines should be filled in, likewise screw holes and molded-in "bolt heads". The distinctive trapezoidal "grip pads" need to have their lines changed or be removed. Get rid of the cocking handles or drastically alter them into something else. A good general policy is to rip out the workings or otherwise render them firing-inactive. Lop off other recognizable bits. Replace things with other things -- either from other Nerfs, modded, or from the plumbing or electrical aisles at your local hardware store. Change the general lines. And, of course, add random cool-looking greeblies and a big scope or other targeting device.
As an example, here's a mod I've tinkered with over the last couple years:
I'm turning a Longshot and Recon into something intended to be a squad automatic weapon "big brother" to the Uzi-based Supertrooper auto-blaster (bearign in mind in this picture the barrel's been twisted 90° from how it was originally):
See what I'm doing to eventually make them look like they could have been made by the same arms manufacturer, even though I still have a long way to go?
--Jonah