I looked at a pre-model 10 today, C prefix, 5 screw, round blade front sight, four line address, in about 98% condition. Has newer non-diamond center checkered grips. I do not have the serial #. Any ideas on value?
The stocks on that Pre 10 are not original, should be diamond magnas. Hard to say without a picture and knowing barrel length, but for a ballpark, don't go over $300.
I paid $270 for mine, C prefix serial, 5" bbl, but with ramped front sight. I overpaid a little but I wanted the gun so I was fine with the price.