http://www.fig-soul.com/01/f2_04_07_08_20.php?bang=195
I have this. It's a tiny model giveaway that came with Dengeki hobby (w/o decals). If it is the exact same item.
Not all mecha are bipedal either. They have developed spiderlike forest machines over here. Plenty of use, they can go in environment a wheeled/track vehicle couldn't.
http://www.defensetech.org/archives/001436.html
How about applying a new coat of masking liquid and peeling it off and repeating as necessary. Might work. Didn't read if it was tried though... Tape could do the trick as well.
One of the most beautiful models I have ever seen.