I think you'd be in the vicinity of $1500 with just the gun and box. I understand the gun is high condition, but you didn't mention if the box is in good shape or somewhat worn. Add a hundred or more if it is in excellent condition.
That's without the grip adapter. There has been dispute here in the past about what a K-frame adapter is worth, but I think they are at least $350-400 items, if it is true that the N-frame adapters will bring $750. You'd need a letter to tell if the gun shipped with the adapter. It might be a later add-on. The adapters were available when your gun shipped in 1933.
Put it all together and I think you are near or a little above $2000. You could offer your $1800 to start and come up if need be.
You are obligated to post pictures if you end up with this package.
