Need help with customizations

I've done something very similar to this, but the question in whether you want it to be able to interchange it back to the M14, say, once an airsoft match is over, or if the blaster skin will be permanent. I've actually in the process of converting an airsoft Mauser broomstick into a DL-44 (Like Han Solo's) and its fully functional. The the new barrel is made of a 3/4" PVC coupling, a 3/4" bushing, and the middle part of a industrial thread spool. All in all, I spent maybe $1.50, about 3 hours of work, and two coats of paint, and it can be removed and the old one put back, but I do plan on using PVC cement to make the change permanent.
Also, unless you luck out and find exactly the colour parts you need, you're going to have a hard time getting anything cheap, or anything at all for that matter, that you can find a way around painting. Painting is going to be an integral part of any Mando, Boba or otherwise, anyway you look at it.
But, if you're adamant about not painting, the M14 isn't an entirely un-Mando weapon as it is. I'd just suggest browsing your local hardware stores for greeblies, or anything else that tickles your fancy. I find hardware stores like the Lord of the Rings; you can never see it all in one sitting. Or visit. Hope this helps.
Also, welcome to the community!