The Model 47 was an Experimental 9mm Semi-Auto Pistol S&W produced in the Late 70's!! The main reason most aren't familiar with this Model is the fact that very few are seen with the Original "Model 47" Stamping!! Reason being, most all of these were over-stamped with a (1) Prefix & an (A) Suffix to the "Model 47" Stamping prior to being shipped becoming a "Model 147A" which are also few & far between!!
If you collect S&W 9mm Auto's I'd say it would definitely be in your best interest to grab it if one crosses your path as I believe there were less than 200 of them produced if memory serves!! Hope this helps!!