Next question: for pheasant hunting for example what are the outside parameters of ammo can be shot through this thing safely? (I don't hand reload).

1 1/4oz, 3 1/2 dre. Or more precisely, the then SAAMI max of 10,500 psi loads.

Your gun was likely patterned with 1 1/8oz, 3 dre. If you had the box or the hang tags, they would tell you the patterning load.

I shoot a lot of Great Plains wild pheasants in the wind and cold and use both loads. As to whether those loads can be shot through your gun safely, I don't know, but I do know that Parker guns of your gun's weight and configuration were designed to shoot those loads.

See p.714 TPS for details including service and proof load specifications.