[ILLusion]

I'm comparing the two magazines right now, and I've noticed a few things that may go beyond simple modifications to the lower receiver, but I think with some effort, it can be done:

1) WE magazines are thicker than Tokyo Marui magazines by 1mm. I would recommend WE lower receivers to have the magwell shimmed to prevent wobble, but this may not be necessary. It may just be a minor annoyance at most.

2) Flow valve is in the same loccation. No adjustment to location is necessary.

3) Mag catch notch is a different size. The Tokyo Marui notch is thinner (top to bottom) than the WE notch. The bottom of the notch is in the same place, but the top (where it holds the mag up) is lower on the Marui mag. Thus, the WE mag catch needs material removed from the top, in order to be able to hold up a Tokyo Marui magazine.

4) The magazine guide that inserts in to the notch at the top rear of the magazine protrudes too far to allow a Tokyo Marui magazine to insert all the way. (You've already noticed this.) You would need to file this down to allow a Tokyo Marui magazine to seat completely.

5) The gas route rubber on the Tokyo Marui magazine sits a little bit higher than the WE magazine. Without being able to seat the shell in to the receiver, it's hard to tell what effect this would have. I'd say to take care of the other issues first, and worry about this part once you get to this stage.

Besides that, the feed lips seem to be in the right place, as well as the slide catch trigger.