New member, planning to buy first Parker

[Jose A. Chacon]

Hello, my name is Jose A. Chacon.
Where I live, Mexico City, is really uncommon to find Parkers. Today I visited a person that wants to sell his 12 gauge Parker Bros. This is the first time I have either seen one or put my hands on one of them.
To me it looks in good condition, 30" barrels, serial number 97711, stamped in the barrels it reads "Parker Bros Makers, Meriden, Conn Damasque Steel"
I would appreciate information regarding the following:
Model and grade?
Size of the chambers?
What type of steel is damasque steel? Is it safe to shoot modern low brass shells? ( barrels look in very good condition)
Does the metal color look in original condition? Not re-blued? ( I just got a few pics, if more are needed please tell me).
Without the fore end, barrels and action are a little loose. With the fore end installed the gun is tight. Is this normal/acceptable?
Thank you very much for your help.