You really have no idea, do you? The non-FA version looks a bit odd, but VLTOR makes some of the highest quality AR products of anyone. I have the FA version of the MUR and it is very well made, not cobbled together scrap.
OP: I have three comments on your idea:
1) It will probably work, but might require enlarging the hole where the gas tube would normally go.
2) It's lipstick on a pig.
3) Be aware that the MUR holds tight tolerances and I've found that mine is a very tight fit on several of my lowers. Some people would say this is good, to me it's a nuisance.