...here is a nice -2 3.5" that is already over a grand...
http://nextorch.com/us/product_detail.php?id=55 The uniqueness of the -1 configuration is the guns were only made for ONE year...1960. 1961 started the -2.
The -1 meant that the ejector rod thread was reversed. -2 eliminated the 4th frame screw in front of the triggerguard and the cylinder stop was also changed as a result.... A very rare 3.5 indeed...
Bob