Price of these guns?

[foster]

Can someone tell me what is the value (CDN $$$) of a 16-gauge and a 20-gauge Ivor-Johnson shotguns?
I have a chance to pick these up from a recently widowed woman. She has no clue what they are worth, and neither do I nor any of my friends.
They seem to be in fine shape, as if they were well used in their lifetime but well maintained too.
I think the brand name on them was "Champion."
Thanks in advance for any help you can give.
P.S. I've never owned a 16 or 20-gauge, is ammo readily available?
Are these quite effective on rabbits and grouse?