G&G M14 Scope Mount

Ok so i just got my G&G SOC M14 and I was looking around on Airsoft GI for the scope mount. Now I have found a few some made by CYMA, G&P, TM, CA, and G&G. The CYMA one is the cheepest but it says that it it not compatibale with G&G's. I was just wondering if anyone can verify this because I don't want to spend $50-60 to get either the CA or G&G ones which airsoft GI seems to think are the only compatibale ones. So if you know anything about this please help me out.

G&G Mount - http://www.airsoftgi.com/product_info.php?cPath=36_252&products_id=976

CYMA - http://www.airsoftgi.com/product_info.php?cPath=36_252&products_id=4047

Normally if the manufacturer says it will not work, it won't work.
Why would they purposely limit their sales if it where false?