I'd love to get my hands on a replica of this gun as well, but it's hard to find one. There are, to my knowledge, no accurate airsoft versions of this gun with a 3" heavy barrel.
The ROEHM RG69 blank firing revolver is a close match, but it's very expensive (at least in France, at $300). It's all metal though.
Here's the RG69 :
And the original stainless S&W model 64 :
A resin replica would be great, but in my book nothing comes close to the heavy and cold to the touch feeling of a real gun, even if it's just for display. Even more if it's supposed to be made of stainless steel.
Well nowadays metallic looking paints are quite convicing so even a resin model can be made to look awesome. It's just a matter of finding someone able to find castings of the real gun... :unsure
If were Talking Jack Nicholson Long Barrel Revolver I could get a Couple of Shots of the Original (Screen Used) Gun if anyone wants to try there hand at crafting one.