Hi, I'm in possession of a Nagra IS (it says NAGRA IS-D on the front, but it looks like a IS, so I'm not sure), and I would like to know how much a vintage recorder like that is worth. I found very little information about this device, so any info is welcome, as I know very little about these things. It looks like this : http://schmitronicshop.de/images/DSCN1078.jpg (picture not mine), except there is a label under the name with an engraved number. thanks