New here--trying to help a widow sell a gun and figured this might be a good place to start. I'd be happy to take it myself but I am certain it's worth more than I can afford. We need to establish value.

It's a model 99 in 250-3000 with the thin schnabel forend. Serial # 566XXX. We think mid 50's but not certain.

Any links to serial xx's by date, and info on identifying models by date?

I need to see the gun to get more specs but as I recall it was in good but used condition, with some case coloring left and some type of peep site--just can't remember if it was flip up tang or receiver mount. I know it had a peep site as she'd asked me to help her sight it in for deer hunting, and my first shot was an inch high dead center, and the next one was maybe 1/2" from that. I don't shoot that well with leaf sights... :)

Any help appreciated!