Frame
Impossible to answer without a serial number.
1956
1954-58
With the serial number that you have provided,your Hi standard M-101,.22cal pistol was made in the year 1955.
Between 1971-1973.
Good 22.
1-40,9061
Check the receiver and barrel
Buy one of the books that has published serial numbers for that particular pistol.
You can look up serial numbers at Proofhouse.com
The only way to find out how old a Bretta automatic pistol with the serial number 605222 is to call the company. There is not a listing for Bretta's by serial numbers online.
serial numbers are of no value without the makers name, model of pistol, caliber and overall condition.....................