I AGREE TOTALLY!! SAF, you already look good, you are just going to ruin your physique if you keep your carbs that low for 4 weeks straight. That's for people who are still fat at this point. You are not fat. At the very least, keep them low like you have them for 2-3 days, then have a higher carb day (~300g).
Here's a couple of more tips for the last week of your show:
(1) Don't change your diet until friday. Maybe have a couple of junk meals on friday, and increase carbs a bit, but that's it. Don't decarb then recarb-up during the last week. I tried that in my show ~a month ago and it doesn't fucking work! I looked better a week out than the day of the show.
(2) Keep your water as high as you can until you cut it out. Cut it out on friday morning or friday night (depending on whether or not you are trying to make a weight class), take a diuretic (lasix, Hctz), then just sip until you go on stage. If your not trying to make a weight class at the weigh-in friday night, cut your water only friday night.
Good luck!