Primers are easy to check.
Just install a few in empty hulls and fire them in the gun.
If they go bang, and sound normal, they're more than likely good.
Although primers can suffer deterioration and be less than effective.
And that alone can affect how the loaded round acts.
Maybe ok, maybe not.
Powder that old would be suspicious.
If the containers had never been opened, maybe.
But if they were exposed to the air, it's doubtful.
Check the odor.
Bad powder usually smells vinegary.
But it would still be mighty suspicious, if it didn't.
Powder is cheap, just buy some.
As to mixing components, absolutely NO.
Reloading for shotguns requires following the loading data exactly.
Every single component in the load must agree with the data.
Hulls, wads, powder, amount of pellets, every single thing.
Shotguns are relatively low pressure devices.
They don't tolerate reloading errors well.
Get yourself a reloading manual and follow it as if it were the the Last Word.