I completely sympathize with your sentiments. I went through this last year - I was looking for a 3" 657 or 629 and found it hard to get one. Currently, they will set you back $700 to $1k from the ones I can find. Basically, it's going to be hard to beat the cost of just getting a factory one to begin with - a decent 657 is going to run you about $550, plus say $50 shipping and a transfer fee. Shipping it back to a gunsmith and the labor to cut the barrel, recrown the muzzle, and re-install an aftermarket front sight is going to be about $200 minimum from what I priced. You are going to also have to re-blade the rear sight if you start with a 6" gun ($25 or more), and do a fair amount of polishing to the front barrel to remove the cut-through "Smith & Wesson" and caliber markings on the longer barrel. Some 4" guns you can get away with this if you bob it back to only 3 1/4". And round butting the grip frame and getting some nice wood combat stocks on it that work well is likely another $125.
So, all in , you'll be about $900 for a cut-up gun that you likely could have bought for $850 with some careful and diligent shopping. Check the classifieds on the gun boards, GB and AA (ignore the rip-off dealers asking $1100 - they are for the impulsive and aren't realistic prices, anyway).
Even if you've already got the gun, it might be better to sell it, add a few hundred to it and buy the factory built thing than going to the hassle of a conversion.
