Do you have anything else with it, box, etc.? It dates to 1955 with that SN and looks in excellent condition. SCSW gives ANIB value at $2700, EXC at $1500 (2016 pricing). Nickel brings a premium. Given what I've see a few numbered model 27 guns go for lately, I'd put the value of this one north of $2K.
For insurance purposes, I would think not less than $2000. Just try to find a replacement in like condition!!
Here is one, a little nicer with the box and stuff, but blued. I am seeing very few of these on closed auctions. This one brought $2500.
Overall, I think the $2000 plus is a good number, Thanks
Just a moment...
That's a sweet revolver! Here's its cousin, my 1955 .357 Magnum...