I have a Winchester M97 made in 1910. Picked her up at an Oklahoma gun show in Chickasha a year ago for $375. Full choke, 16 Guage, very good working condition. I'd like to use it for waterfowl but I am very hesitant to pul steel waterfowl shot in her and watch it go. Its not going to be a safe queen- If I cant hunt with it I'm going to sell or trade it for an Ithaca M37.

Is there any alternative to Steel shot that is safer to shoot? Bismuth...etc? Finding non-toxic 16 gauge ammo is a pain, so if you know not just who makes it but who carries it, I'd be very grateful. Anyone with insight in shooting these older shotguns would be appreciated.

Just get a new (used) bbl, put the original one aside, & go to town.  Bismuth, Hevi-Shot, etc, will give slightly more range, but you'll pay though the nose if you can find it.  Best to reload 16 ga.

I have a 1898 made takedown w/ factory letter.  

This stuff is designed to be fired through older guns, it's as soft as/softer than lead, andwont mess the barrel up
http://www.niceshotinc.com/
Your other option is heavi shot classic doubles, but I don't remember if they make it
In 16

Kent and Rio both load bismuth loads.  Safe for old barrels.  I haven't looked in a while, but I know Rio offers bismuth in 16 gauge.  Hevishot classic doubles as mentioned is an option as well.  I used to shoot that through a 16 gauge full choke wingmaster.

The upside to heavishot is that you can go back to #6 for ducks,
I have nothing but good things to say about their products, for the last 2 years heavi metal #4s have but everything I've pointed the gun(Saiga) at into the boat, from teal to greater Canadas