Purchased one of these yesterday and have questions, 1. How rare are they? 2. How collectable are they? 3 What value should I place on it? It is unspun and unfired, if not collectable or valuable I'm going to shoot it.
I think your use of the word "conversion" has caused some confusion, hence the lack of replies to your query. Convertible, perhaps?
The S4440 is a somewhat rare variety with around 1,200 produced according to the R.E.N.E.. Current values are in the $700 range.
Note the nomenclature rollmarked on the cylinder frame labeling the gun as a Blackhawk. The unfluted cylinders, large grip frame and Super Blackhawk hammer shows us something more like a Super Blackhawk, eh? The model number, S4440, is similar to the Super Blackhawk's model numbers, too.
PS Note that the .44-40 cylinders are dimensioned to utilize 0.427" bullets however the barrel is Ruger's standard .44 sized which is designed around the common .44 magnum bullets of 0.429"/0.430".