Besafe - I am afraid that it is not that simple. Welcome to the world of Colt. While it is generally true that Green Label rifles do not have a sear block and do have a large front pin, it is not written in stone. Colt did some odd things. The same holds true for Blue Label Colts. I have seen them with every combination of sear block, large front pin, small front pin and raised mag fence. My Blue Label has a large front pin. My friend has one with a serial number that is close to mine, but with a small front pin. The only way you will know for sure is to inspect the rifle in which you are interested or ask questions of the seller if buying mail order. With Colt there are no hard and fast rules.