Doc41- getting back to your original question . . . .
I bought a blued 4" Python two years ago - no box or papers. Factory wood grips but the serial # on the grips do not match the pistol. Condition - about 98% and I say that as there is just a slight touch of blue wear on one side of the muzzle but not completely gone. The pistol didn't appear to have been shot very much at all. At the time, I paid $800 for it and I consider that I got it at a "steal" price wise. Basically, I purchased it as an investment - I've shot it some but I much prefer more "vintage" revolvers. A short time after I purchased mine, I was in a LGS and they had just had a blued 6" come in - they had a $800 tag on it - no box or papers. Like and idiot, I hesitated. I went back for it the next day and alas, it was gone. . . duh!
From the few I've been running across - a blued 4" is running around $1,000 up. I would think $1,000 for a good one with a little wear would not be unreasonable - perhaps even more than that. If I was going to sell mine, I'd be asking $1,200 and go frome there. I might be right, I might be wrong. I was shooting mine at an indoor range in Tucson a year ago and a guy was watching me. I invited him to try it and he put two cylinders full through it. He offerec me $1,000 for it knowing that I had no box or papers as he had asked. I politely declined - he upped the offer until I got it across to him that it wasn't for sale.
Check on the Colt Forum though as they'll have a better idea of the value.