I could have just totally ignore this post, since the seller actually bought the magazines from me.
They were fitting perfectly on my G&Ps ( although I have heard G&P doesn't go well with some other brands), Hicap BB loader doesn't work well with the magazines ( I have a KA 500cap loader).
About the issues of the super glue & stripped screw, I have no idea. I basically followed the instruction of installing the magpul base plates with a small Hex, so I didn't use any glue at all.
You have a VFC 416 correct?