You can't put a price on old family memories. But $400 and some ammo seems like a fair price and value.
As a boy visiting my grandparents' house in Northern Pa., I remember sorting through the ammunition in the bottom cupboard of the gun cabinet. The best smelling stuff in the world is old used paper shotgun shells. I still remember the Remington/Peters "punkin balls" ammunition. Just a round musket ball in a paper hull.
My dad explained the balls were not very accurate, but in the woods, he and his dad and uncles took plenty of deer at less than 25 yards and they did the job. That would have been the late '40s and 50's. Maybe earlier, but my dad would not have remembered. Those iron sights were a big deal, back in the day.
My love for the Model 37 started in my dad's old bedroom, where I stayed when visiting my grandmother as a six year old. The pictures engraved in the receiver still make me happy. My dad explained that 16 gauge, like his, was the gentleman's gun. Not too small and not too big, perfect for grouse hunting. He said pheasant hunting, like shown in the engraving, was for fellas who didn't live up in the hills.
Well, maybe that's why I have a dog, and why I think of my dad every time we step into the field. Priceless.
If I was looking for a ranch gun, something to deal with raccoons in the trash or at the chicken coop... what a classy old thing to keep high on the kitchen shelf near the back door!