ID a pistol...

I was asked by my Dad to ID a pistol for him,  The only ID markings on it are a 7...  The rest is pitted, The other side has "PS" on it.  From the looks of it I believed it to be a Tokorav varient or another combloc firearm due to the rounded end of the slide and the shape of the pistol grip.  I believe that the pistol may be a .25 caliber from the size, it is hard to deduce from a photo.   I am hoping others are more knowledgeable than I am.  I am not afraid to ask for help.)   I was told that it is a pretty old gun.

    Here is the photo