There's a used Blackhawk I'm eyeing at the shop. It's a convertible model, with the spare 9mm cylinder, and has a 6-inch barrel. I'm mostly an autopistol guy, and the only SA revolver I've shot was a .22. They're asking $329, which seems to be a real good deal to me. I'm wondering how old it may be. The serial number starts with 33 and ends in 66. It apparently doesn't have a half-cock setting for the hammer, the cylinder "free-wheels" when the hammer is down. Is this the old model of the new model? What are the advantages/disadvantages of the new model vs. the old? Any other general information about SA revolvers would be appreciated and other recommendations, if necessary, would also be appreciated.