Proofhouse.com has sn tables you look up
Proofhouse.com has Colt serial numbers you can look up
Take your pick. Various Colt serial numbers and dates.cut & paste http://www.proofhouse.com/colt/index.html
go to proofhouse .com and click colt serial numbers,this will tell you the age of your colt.
is that four numbers or five numbers in serial number ?????
You will have to call Colt. Published serial numbers stop at 1978
The Colt model 1911 commercial .45 with serial # 70G67301was produced in 1974.The serial numbers in 1975started with 70G73001.
Go here - http://proofhouse.com/colt/index.html
You can find a list of Colt M1911 and M1911A1 production serial numbers at http://www.coolgunsite.com/pistols/colt%20production.htm. Going by the numbers in your question (7071), it looks like you have a M1911 that was made for the Navy in 1912, the first year of production.
Around 1916
Made in 1951 - There were 8,011 made that year, serial numbers #62,629 - #70,639
Unless you provide the model, your question is almost impossible to answer. If you don't want to, go to Proofhouse.com and research the Colt serial numbers.
Proofhouse.com has a list of serial numbers that can help you.