The loading gate number isn't supposed to match the rest of the serial numbers. That number is an assembly number.
Looks like a nice original SAA
I'm no good estimating SAA values. Someone else will be along with an opinion that would be better than mine.
Bit dubious on the frame stampings, they appear quite rough, also the rampant colt does not appear within a circle. I could be very wrong, but for 1903 serial she should have the serial on the trigger guard frame as well as the grip frame. The VP mark appears in the correct spot, is there another mark there, cannot make it out clearly in the photo. Would not at this time hazard a guess as to its worth.
The serial is 341,505 isn't it? The first digit is hard to read from the picture, but the font style of the numbers don't look anything like what they should look like in the 241,xxx range. If 341,505 it's about a 1921 production and there would be no circle around the horse and that's why you don't see a number on the triggerguard....it's stamped on the grip straps under the grips. You very well may see the last 2 digits of the serial number on the back of the cylinder.
I'm going to say you'll see these at shows from $1,600 to $1,800 for folks wanting to sell them up to $2,500 for those who don't want to sell. My last trip to the Tulsa show had the same basic single actions scattered all around the show and there wasn't any rhyme or reason to the pricing because of the hugh spreads in the price tags.